[GuardWidening] Support widening of explicitly expressed guards

This patch adds support of guards expressed in explicit form via
`widenable_condition` in Guard Widening pass.

Differential Revision: https://reviews.llvm.org/D56075
Reviewed By: reames

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353932 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/GuardWidening.cpp b/lib/Transforms/Scalar/GuardWidening.cpp
index b7988f21479f104189997c2226b8a025b26ed433..01ae9179f4ec0b68d6bc97df8b17e459e2ba42da 100644 (file)
--- a/lib/Transforms/Scalar/GuardWidening.cpp
+++ b/lib/Transforms/Scalar/GuardWidening.cpp
@@ -82,6 +82,11 @@ static cl::opt<unsigned> FrequentBranchThreshold(
              "it is considered frequently taken"),
     cl::init(1000));
 
+static cl::opt<bool>
+    WidenBranchGuards("guard-widening-widen-branch-guards", cl::Hidden,
+                      cl::desc("Whether or not we should widen guards  "
+                               "expressed as branches by widenable conditions"),
+                      cl::init(true));
 
 namespace {
 
@@ -92,6 +97,10 @@ static Value *getCondition(Instruction *I) {
            "Bad guard intrinsic?");
     return GI->getArgOperand(0);
   }
+  if (isGuardAsWidenableBranch(I)) {
+    auto *Cond = cast<BranchInst>(I)->getCondition();
+    return cast<BinaryOperator>(Cond)->getOperand(0);
+  }
   return cast<BranchInst>(I)->getCondition();
 }
 
@@ -262,8 +271,16 @@ class GuardWideningImpl {
   void widenGuard(Instruction *ToWiden, Value *NewCondition,
                   bool InvertCondition) {
     Value *Result;
-    widenCondCommon(ToWiden->getOperand(0), NewCondition, ToWiden, Result,
+    widenCondCommon(getCondition(ToWiden), NewCondition, ToWiden, Result,
                     InvertCondition);
+    Value *WidenableCondition = nullptr;
+    if (isGuardAsWidenableBranch(ToWiden)) {
+      auto *Cond = cast<BranchInst>(ToWiden)->getCondition();
+      WidenableCondition = cast<BinaryOperator>(Cond)->getOperand(1);
+    }
+    if (WidenableCondition)
+      Result = BinaryOperator::CreateAnd(Result, WidenableCondition,
+                                         "guard.chk", ToWiden);
     setCondition(ToWiden, Result);
   }
 
@@ -281,6 +298,14 @@ public:
 };
 }
 
+static bool isSupportedGuardInstruction(const Instruction *Insn) {
+  if (isGuard(Insn))
+    return true;
+  if (WidenBranchGuards && isGuardAsWidenableBranch(Insn))
+    return true;
+  return false;
+}
+
 bool GuardWideningImpl::run() {
   DenseMap<BasicBlock *, SmallVector<Instruction *, 8>> GuardsInBlock;
   bool Changed = false;
@@ -300,7 +325,7 @@ bool GuardWideningImpl::run() {
     auto &CurrentList = GuardsInBlock[BB];
 
     for (auto &I : *BB)
-      if (isGuard(&I))
+      if (isSupportedGuardInstruction(&I))
         CurrentList.push_back(cast<Instruction>(&I));
 
     for (auto *II : CurrentList)
@@ -322,7 +347,7 @@ bool GuardWideningImpl::run() {
   for (auto *I : EliminatedGuardsAndBranches)
     if (!WidenedGuards.count(I)) {
       assert(isa<ConstantInt>(getCondition(I)) && "Should be!");
-      if (isGuard(I))
+      if (isSupportedGuardInstruction(I))
         eliminateGuard(I);
       else {
         assert(isa<BranchInst>(I) &&
@@ -452,6 +477,8 @@ GuardWideningImpl::computeWideningScore(Instruction *DominatedInstr,
   auto MaybeHoistingOutOfIf = [&]() {
     auto *DominatingBlock = DominatingGuard->getParent();
     auto *DominatedBlock = DominatedInstr->getParent();
+    if (isGuardAsWidenableBranch(DominatingGuard))
+      DominatingBlock = cast<BranchInst>(DominatingGuard)->getSuccessor(0);
 
     // Same Block?
     if (DominatedBlock == DominatingBlock)

diff --git a/test/Transforms/GuardWidening/basic_widenable_condition_guards.ll b/test/Transforms/GuardWidening/basic_widenable_condition_guards.ll
new file mode 100644 (file)
index 0000000..605178a
--- /dev/null
+++ b/test/Transforms/GuardWidening/basic_widenable_condition_guards.ll
@@ -0,0 +1,1041 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -guard-widening-widen-branch-guards=true -guard-widening < %s        | FileCheck %s
+; RUN: opt -S -guard-widening-widen-branch-guards=true -passes=guard-widening < %s | FileCheck %s
+
+; Basic test case: we wide the first check to check both the
+; conditions.
+define void @f_0(i1 %cond_0, i1 %cond_1) {
+; CHECK-LABEL: @f_0(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[WIDENABLE_COND:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND:%.*]] = and i1 [[COND_0:%.*]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    [[WIDE_CHK:%.*]] = and i1 [[COND_0]], [[COND_1:%.*]]
+; CHECK-NEXT:    [[GUARD_CHK:%.*]] = and i1 [[WIDE_CHK]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    br i1 [[GUARD_CHK]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof !0
+; CHECK:       deopt:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded:
+; CHECK-NEXT:    [[WIDENABLE_COND3:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND4:%.*]] = and i1 [[COND_1]], [[WIDENABLE_COND3]]
+; CHECK-NEXT:    br i1 true, label [[GUARDED1:%.*]], label [[DEOPT2:%.*]], !prof !0
+; CHECK:       deopt2:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded1:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %widenable_cond = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond = and i1 %cond_0, %widenable_cond
+  br i1 %exiplicit_guard_cond, label %guarded, label %deopt, !prof !0
+
+deopt:                                            ; preds = %entry
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded:                                          ; preds = %entry
+  %widenable_cond3 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond4 = and i1 %cond_1, %widenable_cond3
+  br i1 %exiplicit_guard_cond4, label %guarded1, label %deopt2, !prof !0
+
+deopt2:                                           ; preds = %guarded
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded1:                                         ; preds = %guarded
+  ret void
+}
+
+; Same as @f_0, but with using a more general notion of postdominance.
+define void @f_1(i1 %cond_0, i1 %cond_1) {
+; CHECK-LABEL: @f_1(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[WIDENABLE_COND:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND:%.*]] = and i1 [[COND_0:%.*]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    [[WIDE_CHK:%.*]] = and i1 [[COND_0]], [[COND_1:%.*]]
+; CHECK-NEXT:    [[GUARD_CHK:%.*]] = and i1 [[WIDE_CHK]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    br i1 [[GUARD_CHK]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof !0
+; CHECK:       deopt:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded:
+; CHECK-NEXT:    br i1 undef, label [[LEFT:%.*]], label [[RIGHT:%.*]]
+; CHECK:       left:
+; CHECK-NEXT:    br label [[MERGE:%.*]]
+; CHECK:       right:
+; CHECK-NEXT:    br label [[MERGE]]
+; CHECK:       merge:
+; CHECK-NEXT:    [[WIDENABLE_COND3:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND4:%.*]] = and i1 [[COND_1]], [[WIDENABLE_COND3]]
+; CHECK-NEXT:    br i1 true, label [[GUARDED1:%.*]], label [[DEOPT2:%.*]], !prof !0
+; CHECK:       deopt2:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded1:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %widenable_cond = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond = and i1 %cond_0, %widenable_cond
+  br i1 %exiplicit_guard_cond, label %guarded, label %deopt, !prof !0
+
+deopt:                                            ; preds = %entry
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded:                                          ; preds = %entry
+  br i1 undef, label %left, label %right
+
+left:                                             ; preds = %guarded
+  br label %merge
+
+right:                                            ; preds = %guarded
+  br label %merge
+
+merge:                                            ; preds = %right, %left
+  %widenable_cond3 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond4 = and i1 %cond_1, %widenable_cond3
+  br i1 %exiplicit_guard_cond4, label %guarded1, label %deopt2, !prof !0
+
+deopt2:                                           ; preds = %merge
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded1:                                         ; preds = %merge
+  ret void
+}
+
+; Like @f_1, but we have some code we need to hoist before we can
+; widen a dominanting check.
+define void @f_2(i32 %a, i32 %b) {
+; CHECK-LABEL: @f_2(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[COND_0:%.*]] = icmp ult i32 [[A:%.*]], 10
+; CHECK-NEXT:    [[WIDENABLE_COND:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND:%.*]] = and i1 [[COND_0]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    [[COND_1:%.*]] = icmp ult i32 [[B:%.*]], 10
+; CHECK-NEXT:    [[WIDE_CHK:%.*]] = and i1 [[COND_0]], [[COND_1]]
+; CHECK-NEXT:    [[GUARD_CHK:%.*]] = and i1 [[WIDE_CHK]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    br i1 [[GUARD_CHK]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof !0
+; CHECK:       deopt:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded:
+; CHECK-NEXT:    br i1 undef, label [[LEFT:%.*]], label [[RIGHT:%.*]]
+; CHECK:       left:
+; CHECK-NEXT:    br label [[MERGE:%.*]]
+; CHECK:       right:
+; CHECK-NEXT:    br label [[MERGE]]
+; CHECK:       merge:
+; CHECK-NEXT:    [[WIDENABLE_COND3:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND4:%.*]] = and i1 [[COND_1]], [[WIDENABLE_COND3]]
+; CHECK-NEXT:    br i1 true, label [[GUARDED1:%.*]], label [[DEOPT2:%.*]], !prof !0
+; CHECK:       deopt2:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded1:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %cond_0 = icmp ult i32 %a, 10
+  %widenable_cond = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond = and i1 %cond_0, %widenable_cond
+  br i1 %exiplicit_guard_cond, label %guarded, label %deopt, !prof !0
+
+deopt:                                            ; preds = %entry
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded:                                          ; preds = %entry
+  br i1 undef, label %left, label %right
+
+left:                                             ; preds = %guarded
+  br label %merge
+
+right:                                            ; preds = %guarded
+  br label %merge
+
+merge:                                            ; preds = %right, %left
+  %cond_1 = icmp ult i32 %b, 10
+  %widenable_cond3 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond4 = and i1 %cond_1, %widenable_cond3
+  br i1 %exiplicit_guard_cond4, label %guarded1, label %deopt2, !prof !0
+
+deopt2:                                           ; preds = %merge
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded1:                                         ; preds = %merge
+  ret void
+}
+
+; Negative test: don't hoist stuff out of control flow
+; indiscriminately, since that can make us do more work than needed.
+define void @f_3(i32 %a, i32 %b) {
+; CHECK-LABEL: @f_3(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[COND_0:%.*]] = icmp ult i32 [[A:%.*]], 10
+; CHECK-NEXT:    [[WIDENABLE_COND:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND:%.*]] = and i1 [[COND_0]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    br i1 [[EXIPLICIT_GUARD_COND]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof !0
+; CHECK:       deopt:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded:
+; CHECK-NEXT:    br i1 undef, label [[LEFT:%.*]], label [[RIGHT:%.*]]
+; CHECK:       left:
+; CHECK-NEXT:    [[COND_1:%.*]] = icmp ult i32 [[B:%.*]], 10
+; CHECK-NEXT:    [[WIDENABLE_COND3:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND4:%.*]] = and i1 [[COND_1]], [[WIDENABLE_COND3]]
+; CHECK-NEXT:    br i1 [[EXIPLICIT_GUARD_COND4]], label [[GUARDED1:%.*]], label [[DEOPT2:%.*]], !prof !0
+; CHECK:       deopt2:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded1:
+; CHECK-NEXT:    ret void
+; CHECK:       right:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %cond_0 = icmp ult i32 %a, 10
+  %widenable_cond = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond = and i1 %cond_0, %widenable_cond
+  br i1 %exiplicit_guard_cond, label %guarded, label %deopt, !prof !0
+
+deopt:                                            ; preds = %entry
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded:                                          ; preds = %entry
+  br i1 undef, label %left, label %right
+
+left:                                             ; preds = %guarded
+  %cond_1 = icmp ult i32 %b, 10
+  %widenable_cond3 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond4 = and i1 %cond_1, %widenable_cond3
+  br i1 %exiplicit_guard_cond4, label %guarded1, label %deopt2, !prof !0
+
+deopt2:                                           ; preds = %left
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded1:                                         ; preds = %left
+  ret void
+
+right:                                            ; preds = %guarded
+  ret void
+}
+
+; But hoisting out of control flow is fine if it makes a loop computed
+; condition loop invariant.  This behavior may require some tuning in
+; the future.
+define void @f_4(i32 %a, i32 %b) {
+; CHECK-LABEL: @f_4(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[COND_0:%.*]] = icmp ult i32 [[A:%.*]], 10
+; CHECK-NEXT:    [[WIDENABLE_COND:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND:%.*]] = and i1 [[COND_0]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    [[COND_1:%.*]] = icmp ult i32 [[B:%.*]], 10
+; CHECK-NEXT:    [[WIDE_CHK:%.*]] = and i1 [[COND_0]], [[COND_1]]
+; CHECK-NEXT:    [[GUARD_CHK:%.*]] = and i1 [[WIDE_CHK]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    br i1 [[GUARD_CHK]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof !0
+; CHECK:       deopt:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded:
+; CHECK-NEXT:    br i1 undef, label [[LOOP:%.*]], label [[LEAVE:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[WIDENABLE_COND3:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND4:%.*]] = and i1 [[COND_1]], [[WIDENABLE_COND3]]
+; CHECK-NEXT:    br i1 true, label [[GUARDED1:%.*]], label [[DEOPT2:%.*]], !prof !0
+; CHECK:       deopt2:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded1:
+; CHECK-NEXT:    br i1 undef, label [[LOOP]], label [[LEAVE]]
+; CHECK:       leave:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %cond_0 = icmp ult i32 %a, 10
+  %widenable_cond = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond = and i1 %cond_0, %widenable_cond
+  br i1 %exiplicit_guard_cond, label %guarded, label %deopt, !prof !0
+
+deopt:                                            ; preds = %entry
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded:                                          ; preds = %entry
+  br i1 undef, label %loop, label %leave
+
+loop:                                             ; preds = %guarded1, %guarded
+  %cond_1 = icmp ult i32 %b, 10
+  %widenable_cond3 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond4 = and i1 %cond_1, %widenable_cond3
+  br i1 %exiplicit_guard_cond4, label %guarded1, label %deopt2, !prof !0
+
+deopt2:                                           ; preds = %loop
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded1:                                         ; preds = %loop
+  br i1 undef, label %loop, label %leave
+
+leave:                                            ; preds = %guarded1, %guarded
+  ret void
+}
+
+; Hoisting out of control flow is also fine if we can widen the
+; dominating check without doing any extra work.
+define void @f_5(i32 %a) {
+; CHECK-LABEL: @f_5(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[COND_0:%.*]] = icmp ugt i32 [[A:%.*]], 7
+; CHECK-NEXT:    [[WIDENABLE_COND:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND:%.*]] = and i1 [[COND_0]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    [[WIDE_CHK:%.*]] = icmp uge i32 [[A]], 11
+; CHECK-NEXT:    [[GUARD_CHK:%.*]] = and i1 [[WIDE_CHK]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    br i1 [[GUARD_CHK]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof !0
+; CHECK:       deopt:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded:
+; CHECK-NEXT:    br i1 undef, label [[LEFT:%.*]], label [[RIGHT:%.*]]
+; CHECK:       left:
+; CHECK-NEXT:    [[COND_1:%.*]] = icmp ugt i32 [[A]], 10
+; CHECK-NEXT:    [[WIDENABLE_COND3:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND4:%.*]] = and i1 [[COND_1]], [[WIDENABLE_COND3]]
+; CHECK-NEXT:    br i1 true, label [[GUARDED1:%.*]], label [[DEOPT2:%.*]], !prof !0
+; CHECK:       deopt2:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded1:
+; CHECK-NEXT:    ret void
+; CHECK:       right:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %cond_0 = icmp ugt i32 %a, 7
+  %widenable_cond = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond = and i1 %cond_0, %widenable_cond
+  br i1 %exiplicit_guard_cond, label %guarded, label %deopt, !prof !0
+
+deopt:                                            ; preds = %entry
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded:                                          ; preds = %entry
+  br i1 undef, label %left, label %right
+
+left:                                             ; preds = %guarded
+  %cond_1 = icmp ugt i32 %a, 10
+  %widenable_cond3 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond4 = and i1 %cond_1, %widenable_cond3
+  br i1 %exiplicit_guard_cond4, label %guarded1, label %deopt2, !prof !0
+
+deopt2:                                           ; preds = %left
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded1:                                         ; preds = %left
+  ret void
+
+right:                                            ; preds = %guarded
+  ret void
+}
+
+; Negative test: the load from %a can be safely speculated to before
+; the first guard, but there is no guarantee that it will produce the
+; same value.
+define void @f_6(i1* dereferenceable(32) %a, i1* %b, i1 %unknown) {
+; CHECK-LABEL: @f_6(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[COND_0:%.*]] = load i1, i1* [[A:%.*]]
+; CHECK-NEXT:    [[WIDENABLE_COND:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND:%.*]] = and i1 [[COND_0]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    br i1 [[EXIPLICIT_GUARD_COND]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof !0
+; CHECK:       deopt:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded:
+; CHECK-NEXT:    store i1 [[UNKNOWN:%.*]], i1* [[B:%.*]]
+; CHECK-NEXT:    [[COND_1:%.*]] = load i1, i1* [[A]]
+; CHECK-NEXT:    [[WIDENABLE_COND3:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND4:%.*]] = and i1 [[COND_1]], [[WIDENABLE_COND3]]
+; CHECK-NEXT:    br i1 [[EXIPLICIT_GUARD_COND4]], label [[GUARDED1:%.*]], label [[DEOPT2:%.*]], !prof !0
+; CHECK:       deopt2:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded1:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %cond_0 = load i1, i1* %a
+  %widenable_cond = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond = and i1 %cond_0, %widenable_cond
+  br i1 %exiplicit_guard_cond, label %guarded, label %deopt, !prof !0
+
+deopt:                                            ; preds = %entry
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded:                                          ; preds = %entry
+  store i1 %unknown, i1* %b
+  %cond_1 = load i1, i1* %a
+  %widenable_cond3 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond4 = and i1 %cond_1, %widenable_cond3
+  br i1 %exiplicit_guard_cond4, label %guarded1, label %deopt2, !prof !0
+
+deopt2:                                           ; preds = %guarded
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded1:                                         ; preds = %guarded
+  ret void
+}
+
+; All else equal, we try to widen the earliest guard we can.  This
+; heuristic can use some tuning.
+define void @f_7(i32 %a, i1* %cond_buf) {
+; CHECK-LABEL: @f_7(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[COND_1:%.*]] = load volatile i1, i1* [[COND_BUF:%.*]]
+; CHECK-NEXT:    [[WIDENABLE_COND:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND:%.*]] = and i1 [[COND_1]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    [[COND_3:%.*]] = icmp ult i32 [[A:%.*]], 7
+; CHECK-NEXT:    [[WIDE_CHK:%.*]] = and i1 [[COND_1]], [[COND_3]]
+; CHECK-NEXT:    [[GUARD_CHK:%.*]] = and i1 [[WIDE_CHK]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    br i1 [[GUARD_CHK]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof !0
+; CHECK:       deopt:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded:
+; CHECK-NEXT:    [[COND_2:%.*]] = load volatile i1, i1* [[COND_BUF]]
+; CHECK-NEXT:    [[WIDENABLE_COND3:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND4:%.*]] = and i1 [[COND_2]], [[WIDENABLE_COND3]]
+; CHECK-NEXT:    br i1 [[EXIPLICIT_GUARD_COND4]], label [[GUARDED1:%.*]], label [[DEOPT2:%.*]], !prof !0
+; CHECK:       deopt2:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded1:
+; CHECK-NEXT:    br i1 undef, label [[LEFT:%.*]], label [[RIGHT:%.*]]
+; CHECK:       left:
+; CHECK-NEXT:    [[WIDENABLE_COND7:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND8:%.*]] = and i1 [[COND_3]], [[WIDENABLE_COND7]]
+; CHECK-NEXT:    br i1 true, label [[GUARDED5:%.*]], label [[DEOPT6:%.*]], !prof !0
+; CHECK:       deopt6:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded5:
+; CHECK-NEXT:    br label [[LEFT]]
+; CHECK:       right:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %cond_1 = load volatile i1, i1* %cond_buf
+  %widenable_cond = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond = and i1 %cond_1, %widenable_cond
+  br i1 %exiplicit_guard_cond, label %guarded, label %deopt, !prof !0
+
+deopt:                                            ; preds = %entry
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded:                                          ; preds = %entry
+  %cond_2 = load volatile i1, i1* %cond_buf
+  %widenable_cond3 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond4 = and i1 %cond_2, %widenable_cond3
+  br i1 %exiplicit_guard_cond4, label %guarded1, label %deopt2, !prof !0
+
+deopt2:                                           ; preds = %guarded
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded1:                                         ; preds = %guarded
+  br i1 undef, label %left, label %right
+
+left:                                             ; preds = %guarded5, %guarded1
+  %cond_3 = icmp ult i32 %a, 7
+  %widenable_cond7 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond8 = and i1 %cond_3, %widenable_cond7
+  br i1 %exiplicit_guard_cond8, label %guarded5, label %deopt6, !prof !0
+
+deopt6:                                           ; preds = %left
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded5:                                         ; preds = %left
+  br label %left
+
+right:                                            ; preds = %guarded1
+  ret void
+}
+
+; In this case the earliest dominating guard is in a loop, and we
+; don't want to put extra work in there.  This heuristic can use some
+; tuning.
+define void @f_8(i32 %a, i1 %cond_1, i1 %cond_2) {
+; CHECK-LABEL: @f_8(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[WIDENABLE_COND:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND:%.*]] = and i1 [[COND_1:%.*]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    br i1 [[EXIPLICIT_GUARD_COND]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof !0
+; CHECK:       deopt:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded:
+; CHECK-NEXT:    br i1 undef, label [[LOOP]], label [[LEAVE:%.*]]
+; CHECK:       leave:
+; CHECK-NEXT:    [[WIDENABLE_COND3:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND4:%.*]] = and i1 [[COND_2:%.*]], [[WIDENABLE_COND3]]
+; CHECK-NEXT:    [[COND_3:%.*]] = icmp ult i32 [[A:%.*]], 7
+; CHECK-NEXT:    [[WIDE_CHK:%.*]] = and i1 [[COND_2]], [[COND_3]]
+; CHECK-NEXT:    [[GUARD_CHK:%.*]] = and i1 [[WIDE_CHK]], [[WIDENABLE_COND3]]
+; CHECK-NEXT:    br i1 [[GUARD_CHK]], label [[GUARDED1:%.*]], label [[DEOPT2:%.*]], !prof !0
+; CHECK:       deopt2:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded1:
+; CHECK-NEXT:    br i1 undef, label [[LOOP2:%.*]], label [[LEAVE2:%.*]]
+; CHECK:       loop2:
+; CHECK-NEXT:    [[WIDENABLE_COND7:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND8:%.*]] = and i1 [[COND_3]], [[WIDENABLE_COND7]]
+; CHECK-NEXT:    br i1 true, label [[GUARDED5:%.*]], label [[DEOPT6:%.*]], !prof !0
+; CHECK:       deopt6:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded5:
+; CHECK-NEXT:    br label [[LOOP2]]
+; CHECK:       leave2:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %loop
+
+loop:                                             ; preds = %guarded, %entry
+  %widenable_cond = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond = and i1 %cond_1, %widenable_cond
+  br i1 %exiplicit_guard_cond, label %guarded, label %deopt, !prof !0
+
+deopt:                                            ; preds = %loop
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded:                                          ; preds = %loop
+  br i1 undef, label %loop, label %leave
+
+leave:                                            ; preds = %guarded
+  %widenable_cond3 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond4 = and i1 %cond_2, %widenable_cond3
+  br i1 %exiplicit_guard_cond4, label %guarded1, label %deopt2, !prof !0
+
+deopt2:                                           ; preds = %leave
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded1:                                         ; preds = %leave
+  br i1 undef, label %loop2, label %leave2
+
+loop2:                                            ; preds = %guarded5, %guarded1
+  %cond_3 = icmp ult i32 %a, 7
+  %widenable_cond7 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond8 = and i1 %cond_3, %widenable_cond7
+  br i1 %exiplicit_guard_cond8, label %guarded5, label %deopt6, !prof !0
+
+deopt6:                                           ; preds = %loop2
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded5:                                         ; preds = %loop2
+  br label %loop2
+
+leave2:                                           ; preds = %guarded1
+  ret void
+}
+
+; In cases like these where there isn't any "obviously profitable"
+; widening sites, we refuse to do anything.
+define void @f_9(i32 %a, i1 %cond_0, i1 %cond_1) {
+; CHECK-LABEL: @f_9(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[FIRST_LOOP:%.*]]
+; CHECK:       first_loop:
+; CHECK-NEXT:    [[WIDENABLE_COND:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND:%.*]] = and i1 [[COND_0:%.*]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    br i1 [[EXIPLICIT_GUARD_COND]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof !0
+; CHECK:       deopt:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded:
+; CHECK-NEXT:    br i1 undef, label [[FIRST_LOOP]], label [[SECOND_LOOP:%.*]]
+; CHECK:       second_loop:
+; CHECK-NEXT:    [[WIDENABLE_COND3:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND4:%.*]] = and i1 [[COND_1:%.*]], [[WIDENABLE_COND3]]
+; CHECK-NEXT:    br i1 [[EXIPLICIT_GUARD_COND4]], label [[GUARDED1:%.*]], label [[DEOPT2:%.*]], !prof !0
+; CHECK:       deopt2:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded1:
+; CHECK-NEXT:    br label [[SECOND_LOOP]]
+;
+entry:
+  br label %first_loop
+
+first_loop:                                       ; preds = %guarded, %entry
+  %widenable_cond = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond = and i1 %cond_0, %widenable_cond
+  br i1 %exiplicit_guard_cond, label %guarded, label %deopt, !prof !0
+
+deopt:                                            ; preds = %first_loop
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded:                                          ; preds = %first_loop
+  br i1 undef, label %first_loop, label %second_loop
+
+second_loop:                                      ; preds = %guarded1, %guarded
+  %widenable_cond3 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond4 = and i1 %cond_1, %widenable_cond3
+  br i1 %exiplicit_guard_cond4, label %guarded1, label %deopt2, !prof !0
+
+deopt2:                                           ; preds = %second_loop
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded1:                                         ; preds = %second_loop
+  br label %second_loop
+}
+
+; Same situation as in @f_9: no "obviously profitable" widening sites,
+; so we refuse to do anything.
+define void @f_10(i32 %a, i1 %cond_0, i1 %cond_1) {
+; CHECK-LABEL: @f_10(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[WIDENABLE_COND:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND:%.*]] = and i1 [[COND_0:%.*]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    br i1 [[EXIPLICIT_GUARD_COND]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof !0
+; CHECK:       deopt:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded:
+; CHECK-NEXT:    br i1 undef, label [[LOOP]], label [[NO_LOOP:%.*]]
+; CHECK:       no_loop:
+; CHECK-NEXT:    [[WIDENABLE_COND3:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND4:%.*]] = and i1 [[COND_1:%.*]], [[WIDENABLE_COND3]]
+; CHECK-NEXT:    br i1 [[EXIPLICIT_GUARD_COND4]], label [[GUARDED1:%.*]], label [[DEOPT2:%.*]], !prof !0
+; CHECK:       deopt2:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded1:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %loop
+
+loop:                                             ; preds = %guarded, %entry
+  %widenable_cond = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond = and i1 %cond_0, %widenable_cond
+  br i1 %exiplicit_guard_cond, label %guarded, label %deopt, !prof !0
+
+deopt:                                            ; preds = %loop
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded:                                          ; preds = %loop
+  br i1 undef, label %loop, label %no_loop
+
+no_loop:                                          ; preds = %guarded
+  %widenable_cond3 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond4 = and i1 %cond_1, %widenable_cond3
+  br i1 %exiplicit_guard_cond4, label %guarded1, label %deopt2, !prof !0
+
+deopt2:                                           ; preds = %no_loop
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded1:                                         ; preds = %no_loop
+  ret void
+}
+
+; With guards in loops, we're okay hoisting out the guard into the
+; containing loop.
+define void @f_11(i32 %a, i1 %cond_0, i1 %cond_1) {
+; CHECK-LABEL: @f_11(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[OUTER_HEADER:%.*]]
+; CHECK:       outer_header:
+; CHECK-NEXT:    [[WIDENABLE_COND:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND:%.*]] = and i1 [[COND_0:%.*]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    [[WIDE_CHK:%.*]] = and i1 [[COND_0]], [[COND_1:%.*]]
+; CHECK-NEXT:    [[GUARD_CHK:%.*]] = and i1 [[WIDE_CHK]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    br i1 [[GUARD_CHK]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof !0
+; CHECK:       deopt:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded:
+; CHECK-NEXT:    br label [[INNER:%.*]]
+; CHECK:       inner:
+; CHECK-NEXT:    [[WIDENABLE_COND3:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND4:%.*]] = and i1 [[COND_1]], [[WIDENABLE_COND3]]
+; CHECK-NEXT:    br i1 true, label [[GUARDED1:%.*]], label [[DEOPT2:%.*]], !prof !0
+; CHECK:       deopt2:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded1:
+; CHECK-NEXT:    br i1 undef, label [[INNER]], label [[OUTER_LATCH:%.*]]
+; CHECK:       outer_latch:
+; CHECK-NEXT:    br i1 undef, label [[OUTER_HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %outer_header
+
+outer_header:                                     ; preds = %outer_latch, %entry
+  %widenable_cond = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond = and i1 %cond_0, %widenable_cond
+  br i1 %exiplicit_guard_cond, label %guarded, label %deopt, !prof !0
+
+deopt:                                            ; preds = %outer_header
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded:                                          ; preds = %outer_header
+  br label %inner
+
+inner:                                            ; preds = %guarded1, %guarded
+  %widenable_cond3 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond4 = and i1 %cond_1, %widenable_cond3
+  br i1 %exiplicit_guard_cond4, label %guarded1, label %deopt2, !prof !0
+
+deopt2:                                           ; preds = %inner
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded1:                                         ; preds = %inner
+  br i1 undef, label %inner, label %outer_latch
+
+outer_latch:                                      ; preds = %guarded1
+  br i1 undef, label %outer_header, label %exit
+
+exit:                                             ; preds = %outer_latch
+  ret void
+}
+
+; Checks that we are adequately guarded against exponential-time
+; behavior when hoisting code.
+define void @f_12(i32 %a0) {
+; CHECK-LABEL: @f_12(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[WIDENABLE_COND:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND:%.*]] = and i1 true, [[WIDENABLE_COND]]
+; CHECK-NEXT:    [[A1:%.*]] = mul i32 [[A0:%.*]], [[A0]]
+; CHECK-NEXT:    [[A2:%.*]] = mul i32 [[A1]], [[A1]]
+; CHECK-NEXT:    [[A3:%.*]] = mul i32 [[A2]], [[A2]]
+; CHECK-NEXT:    [[A4:%.*]] = mul i32 [[A3]], [[A3]]
+; CHECK-NEXT:    [[A5:%.*]] = mul i32 [[A4]], [[A4]]
+; CHECK-NEXT:    [[A6:%.*]] = mul i32 [[A5]], [[A5]]
+; CHECK-NEXT:    [[A7:%.*]] = mul i32 [[A6]], [[A6]]
+; CHECK-NEXT:    [[A8:%.*]] = mul i32 [[A7]], [[A7]]
+; CHECK-NEXT:    [[A9:%.*]] = mul i32 [[A8]], [[A8]]
+; CHECK-NEXT:    [[A10:%.*]] = mul i32 [[A9]], [[A9]]
+; CHECK-NEXT:    [[A11:%.*]] = mul i32 [[A10]], [[A10]]
+; CHECK-NEXT:    [[A12:%.*]] = mul i32 [[A11]], [[A11]]
+; CHECK-NEXT:    [[A13:%.*]] = mul i32 [[A12]], [[A12]]
+; CHECK-NEXT:    [[A14:%.*]] = mul i32 [[A13]], [[A13]]
+; CHECK-NEXT:    [[A15:%.*]] = mul i32 [[A14]], [[A14]]
+; CHECK-NEXT:    [[A16:%.*]] = mul i32 [[A15]], [[A15]]
+; CHECK-NEXT:    [[A17:%.*]] = mul i32 [[A16]], [[A16]]
+; CHECK-NEXT:    [[A18:%.*]] = mul i32 [[A17]], [[A17]]
+; CHECK-NEXT:    [[A19:%.*]] = mul i32 [[A18]], [[A18]]
+; CHECK-NEXT:    [[A20:%.*]] = mul i32 [[A19]], [[A19]]
+; CHECK-NEXT:    [[A21:%.*]] = mul i32 [[A20]], [[A20]]
+; CHECK-NEXT:    [[A22:%.*]] = mul i32 [[A21]], [[A21]]
+; CHECK-NEXT:    [[A23:%.*]] = mul i32 [[A22]], [[A22]]
+; CHECK-NEXT:    [[A24:%.*]] = mul i32 [[A23]], [[A23]]
+; CHECK-NEXT:    [[A25:%.*]] = mul i32 [[A24]], [[A24]]
+; CHECK-NEXT:    [[A26:%.*]] = mul i32 [[A25]], [[A25]]
+; CHECK-NEXT:    [[A27:%.*]] = mul i32 [[A26]], [[A26]]
+; CHECK-NEXT:    [[A28:%.*]] = mul i32 [[A27]], [[A27]]
+; CHECK-NEXT:    [[A29:%.*]] = mul i32 [[A28]], [[A28]]
+; CHECK-NEXT:    [[A30:%.*]] = mul i32 [[A29]], [[A29]]
+; CHECK-NEXT:    [[COND:%.*]] = trunc i32 [[A30]] to i1
+; CHECK-NEXT:    [[WIDE_CHK:%.*]] = and i1 true, [[COND]]
+; CHECK-NEXT:    [[GUARD_CHK:%.*]] = and i1 [[WIDE_CHK]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    br i1 [[GUARD_CHK]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof !0
+; CHECK:       deopt:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded:
+; CHECK-NEXT:    [[WIDENABLE_COND3:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND4:%.*]] = and i1 [[COND]], [[WIDENABLE_COND3]]
+; CHECK-NEXT:    br i1 true, label [[GUARDED1:%.*]], label [[DEOPT2:%.*]], !prof !0
+; CHECK:       deopt2:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded1:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %widenable_cond = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond = and i1 true, %widenable_cond
+  br i1 %exiplicit_guard_cond, label %guarded, label %deopt, !prof !0
+
+deopt:                                            ; preds = %entry
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded:                                          ; preds = %entry
+  %a1 = mul i32 %a0, %a0
+  %a2 = mul i32 %a1, %a1
+  %a3 = mul i32 %a2, %a2
+  %a4 = mul i32 %a3, %a3
+  %a5 = mul i32 %a4, %a4
+  %a6 = mul i32 %a5, %a5
+  %a7 = mul i32 %a6, %a6
+  %a8 = mul i32 %a7, %a7
+  %a9 = mul i32 %a8, %a8
+  %a10 = mul i32 %a9, %a9
+  %a11 = mul i32 %a10, %a10
+  %a12 = mul i32 %a11, %a11
+  %a13 = mul i32 %a12, %a12
+  %a14 = mul i32 %a13, %a13
+  %a15 = mul i32 %a14, %a14
+  %a16 = mul i32 %a15, %a15
+  %a17 = mul i32 %a16, %a16
+  %a18 = mul i32 %a17, %a17
+  %a19 = mul i32 %a18, %a18
+  %a20 = mul i32 %a19, %a19
+  %a21 = mul i32 %a20, %a20
+  %a22 = mul i32 %a21, %a21
+  %a23 = mul i32 %a22, %a22
+  %a24 = mul i32 %a23, %a23
+  %a25 = mul i32 %a24, %a24
+  %a26 = mul i32 %a25, %a25
+  %a27 = mul i32 %a26, %a26
+  %a28 = mul i32 %a27, %a27
+  %a29 = mul i32 %a28, %a28
+  %a30 = mul i32 %a29, %a29
+  %cond = trunc i32 %a30 to i1
+  %widenable_cond3 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond4 = and i1 %cond, %widenable_cond3
+  br i1 %exiplicit_guard_cond4, label %guarded1, label %deopt2, !prof !0
+
+deopt2:                                           ; preds = %guarded
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded1:                                         ; preds = %guarded
+  ret void
+}
+
+define void @f_13(i32 %a) {
+; CHECK-LABEL: @f_13(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[COND_0:%.*]] = icmp ult i32 [[A:%.*]], 14
+; CHECK-NEXT:    [[WIDENABLE_COND:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND:%.*]] = and i1 [[COND_0]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    [[WIDE_CHK:%.*]] = icmp ult i32 [[A]], 10
+; CHECK-NEXT:    [[GUARD_CHK:%.*]] = and i1 [[WIDE_CHK]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    br i1 [[GUARD_CHK]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof !0
+; CHECK:       deopt:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded:
+; CHECK-NEXT:    br i1 undef, label [[LEFT:%.*]], label [[RIGHT:%.*]]
+; CHECK:       left:
+; CHECK-NEXT:    [[COND_1:%.*]] = icmp slt i32 [[A]], 10
+; CHECK-NEXT:    [[WIDENABLE_COND3:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND4:%.*]] = and i1 [[COND_1]], [[WIDENABLE_COND3]]
+; CHECK-NEXT:    br i1 true, label [[GUARDED1:%.*]], label [[DEOPT2:%.*]], !prof !0
+; CHECK:       deopt2:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded1:
+; CHECK-NEXT:    ret void
+; CHECK:       right:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %cond_0 = icmp ult i32 %a, 14
+  %widenable_cond = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond = and i1 %cond_0, %widenable_cond
+  br i1 %exiplicit_guard_cond, label %guarded, label %deopt, !prof !0
+
+deopt:                                            ; preds = %entry
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded:                                          ; preds = %entry
+  br i1 undef, label %left, label %right
+
+left:                                             ; preds = %guarded
+  %cond_1 = icmp slt i32 %a, 10
+  %widenable_cond3 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond4 = and i1 %cond_1, %widenable_cond3
+  br i1 %exiplicit_guard_cond4, label %guarded1, label %deopt2, !prof !0
+
+deopt2:                                           ; preds = %left
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded1:                                         ; preds = %left
+  ret void
+
+right:                                            ; preds = %guarded
+  ret void
+}
+
+define void @f_14(i32 %a) {
+; CHECK-LABEL: @f_14(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[COND_0:%.*]] = icmp ult i32 [[A:%.*]], 14
+; CHECK-NEXT:    [[WIDENABLE_COND:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND:%.*]] = and i1 [[COND_0]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    br i1 [[EXIPLICIT_GUARD_COND]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof !0
+; CHECK:       deopt:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded:
+; CHECK-NEXT:    br i1 undef, label [[LEFT:%.*]], label [[RIGHT:%.*]]
+; CHECK:       left:
+; CHECK-NEXT:    [[COND_1:%.*]] = icmp sgt i32 [[A]], 10
+; CHECK-NEXT:    [[WIDENABLE_COND3:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND4:%.*]] = and i1 [[COND_1]], [[WIDENABLE_COND3]]
+; CHECK-NEXT:    br i1 [[EXIPLICIT_GUARD_COND4]], label [[GUARDED1:%.*]], label [[DEOPT2:%.*]], !prof !0
+; CHECK:       deopt2:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded1:
+; CHECK-NEXT:    ret void
+; CHECK:       right:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %cond_0 = icmp ult i32 %a, 14
+  %widenable_cond = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond = and i1 %cond_0, %widenable_cond
+  br i1 %exiplicit_guard_cond, label %guarded, label %deopt, !prof !0
+
+deopt:                                            ; preds = %entry
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded:                                          ; preds = %entry
+  br i1 undef, label %left, label %right
+
+left:                                             ; preds = %guarded
+  %cond_1 = icmp sgt i32 %a, 10
+  %widenable_cond3 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond4 = and i1 %cond_1, %widenable_cond3
+  br i1 %exiplicit_guard_cond4, label %guarded1, label %deopt2, !prof !0
+
+deopt2:                                           ; preds = %left
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded1:                                         ; preds = %left
+  ret void
+
+right:                                            ; preds = %guarded
+  ret void
+}
+
+; Make sure we do not widen guard by trivial true conditions into something.
+define void @f_15(i1 %cond_0, i1 %cond_1) {
+; CHECK-LABEL: @f_15(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[WIDENABLE_COND:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND:%.*]] = and i1 [[COND_0:%.*]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    br i1 [[EXIPLICIT_GUARD_COND]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof !0
+; CHECK:       deopt:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded:
+; CHECK-NEXT:    [[WIDENABLE_COND3:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND4:%.*]] = and i1 true, [[WIDENABLE_COND3]]
+; CHECK-NEXT:    br i1 [[EXIPLICIT_GUARD_COND4]], label [[GUARDED1:%.*]], label [[DEOPT2:%.*]], !prof !0
+; CHECK:       deopt2:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded1:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %widenable_cond = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond = and i1 %cond_0, %widenable_cond
+  br i1 %exiplicit_guard_cond, label %guarded, label %deopt, !prof !0
+
+deopt:                                            ; preds = %entry
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded:                                          ; preds = %entry
+  %widenable_cond3 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond4 = and i1 true, %widenable_cond3
+  br i1 %exiplicit_guard_cond4, label %guarded1, label %deopt2, !prof !0
+
+deopt2:                                           ; preds = %guarded
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded1:                                         ; preds = %guarded
+  ret void
+}
+
+; Make sure we do not widen guard by trivial false conditions into something.
+define void @f_16(i1 %cond_0, i1 %cond_1) {
+; CHECK-LABEL: @f_16(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[WIDENABLE_COND:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND:%.*]] = and i1 [[COND_0:%.*]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    br i1 [[EXIPLICIT_GUARD_COND]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof !0
+; CHECK:       deopt:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded:
+; CHECK-NEXT:    [[WIDENABLE_COND3:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND4:%.*]] = and i1 false, [[WIDENABLE_COND3]]
+; CHECK-NEXT:    br i1 [[EXIPLICIT_GUARD_COND4]], label [[GUARDED1:%.*]], label [[DEOPT2:%.*]], !prof !0
+; CHECK:       deopt2:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded1:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %widenable_cond = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond = and i1 %cond_0, %widenable_cond
+  br i1 %exiplicit_guard_cond, label %guarded, label %deopt, !prof !0
+
+deopt:                                            ; preds = %entry
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded:                                          ; preds = %entry
+  %widenable_cond3 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond4 = and i1 false, %widenable_cond3
+  br i1 %exiplicit_guard_cond4, label %guarded1, label %deopt2, !prof !0
+
+deopt2:                                           ; preds = %guarded
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded1:                                         ; preds = %guarded
+  ret void
+}
+
+declare void @llvm.experimental.deoptimize.isVoid(...)
+
+; Function Attrs: inaccessiblememonly nounwind
+declare i1 @llvm.experimental.widenable.condition() #0
+
+attributes #0 = { inaccessiblememonly nounwind }
+
+!0 = !{!"branch_weights", i32 1048576, i32 1}

diff --git a/test/Transforms/GuardWidening/mixed_guards.ll b/test/Transforms/GuardWidening/mixed_guards.ll
new file mode 100644 (file)
index 0000000..58908c0
--- /dev/null
+++ b/test/Transforms/GuardWidening/mixed_guards.ll
@@ -0,0 +1,74 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -guard-widening-widen-branch-guards=true -guard-widening < %s        | FileCheck %s
+; RUN: opt -S -guard-widening-widen-branch-guards=true -passes=guard-widening < %s | FileCheck %s
+
+; Interaction between intrinsic and widenable condition guards.
+
+declare void @llvm.experimental.guard(i1,...)
+
+declare void @llvm.experimental.deoptimize.isVoid(...)
+
+; Function Attrs: inaccessiblememonly nounwind
+declare i1 @llvm.experimental.widenable.condition() #0
+
+; Widen condition of intrinsic guard with a condition from widenable branch.
+define void @test_01(i1 %cond_0, i1 %cond_1) {
+; CHECK-LABEL: @test_01(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[WIDE_CHK:%.*]] = and i1 [[COND_0:%.*]], [[COND_1:%.*]]
+; CHECK-NEXT:    call void (i1, ...) @llvm.experimental.guard(i1 [[WIDE_CHK]]) [ "deopt"() ]
+; CHECK-NEXT:    [[WIDENABLE_COND3:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND4:%.*]] = and i1 [[COND_1]], [[WIDENABLE_COND3]]
+; CHECK-NEXT:    br i1 true, label [[GUARDED1:%.*]], label [[DEOPT2:%.*]], !prof !0
+; CHECK:       deopt2:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded1:
+; CHECK-NEXT:    ret void
+;
+entry:
+  call void (i1, ...) @llvm.experimental.guard(i1 %cond_0) [ "deopt"() ]
+  %widenable_cond3 = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond4 = and i1 %cond_1, %widenable_cond3
+  br i1 %exiplicit_guard_cond4, label %guarded1, label %deopt2, !prof !0
+
+deopt2:                                           ; preds = %guarded
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded1:                                         ; preds = %guarded
+  ret void
+}
+
+; Widen condition of widenable condition guard with a condition from intrinsic.
+define void @test_02(i1 %cond_0, i1 %cond_1) {
+; CHECK-LABEL: @test_02(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[WIDENABLE_COND:%.*]] = call i1 @llvm.experimental.widenable.condition()
+; CHECK-NEXT:    [[EXIPLICIT_GUARD_COND:%.*]] = and i1 [[COND_0:%.*]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    [[WIDE_CHK:%.*]] = and i1 [[COND_0]], [[COND_1:%.*]]
+; CHECK-NEXT:    [[GUARD_CHK:%.*]] = and i1 [[WIDE_CHK]], [[WIDENABLE_COND]]
+; CHECK-NEXT:    br i1 [[GUARD_CHK]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof !0
+; CHECK:       deopt:
+; CHECK-NEXT:    call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+; CHECK-NEXT:    ret void
+; CHECK:       guarded:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %widenable_cond = call i1 @llvm.experimental.widenable.condition()
+  %exiplicit_guard_cond = and i1 %cond_0, %widenable_cond
+  br i1 %exiplicit_guard_cond, label %guarded, label %deopt, !prof !0
+
+deopt:                                            ; preds = %entry
+  call void (...) @llvm.experimental.deoptimize.isVoid() [ "deopt"() ]
+  ret void
+
+guarded:                                          ; preds = %entry
+  call void (i1, ...) @llvm.experimental.guard(i1 %cond_1) [ "deopt"() ]
+  ret void
+}
+
+attributes #0 = { inaccessiblememonly nounwind }
+
+!0 = !{!"branch_weights", i32 1048576, i32 1}