[Attributor] Restrict liveness and return information to functions

Summary:
Until we have proper call-site information we should not recompute
liveness and return information for each call site. This patch directly
uses the function versions and introduces TODOs at the usage sites.

The required iterations to get to the fixpoint are most of the time
reduced by this change and we always avoid work duplication.

Reviewers: sstefan1, uenoku

Subscribers: hiraditya, bollu, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66562

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@370208 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/IPO/Attributor.cpp b/lib/Transforms/IPO/Attributor.cpp
index a2d470affc0e5a6da7cc0b0612ab7b991d2cbed3..d441012000e90a0d7eb65b71d4460daa1b5373da 100644 (file)
--- a/lib/Transforms/IPO/Attributor.cpp
+++ b/lib/Transforms/IPO/Attributor.cpp
@@ -971,8 +971,16 @@ ChangeStatus AAReturnedValuesImpl::updateImpl(Attributor &A) {
     if (!CB || UnresolvedCalls.count(CB))
       continue;
 
-    const auto &RetValAA =
-        A.getAAFor<AAReturnedValues>(*this, IRPosition::callsite_function(*CB));
+    if (!CB->getCalledFunction()) {
+      LLVM_DEBUG(dbgs() << "[AAReturnedValues] Unresolved call: " << *CB
+                        << "\n");
+      UnresolvedCalls.insert(CB);
+      continue;
+    }
+
+    // TODO: use the function scope once we have call site AAReturnedValues.
+    const auto &RetValAA = A.getAAFor<AAReturnedValues>(
+        *this, IRPosition::function(*CB->getCalledFunction()));
     LLVM_DEBUG(dbgs() << "[AAReturnedValues] Found another AAReturnedValues: "
                       << static_cast<const AbstractAttribute &>(RetValAA)
                       << "\n");
@@ -1070,7 +1078,27 @@ struct AAReturnedValuesFunction final : public AAReturnedValuesImpl {
 };
 
 /// Returned values information for a call sites.
-using AAReturnedValuesCallSite = AAReturnedValuesFunction;
+struct AAReturnedValuesCallSite final : AAReturnedValuesImpl {
+  AAReturnedValuesCallSite(const IRPosition &IRP) : AAReturnedValuesImpl(IRP) {}
+
+  /// See AbstractAttribute::initialize(...).
+  void initialize(Attributor &A) override {
+    // TODO: Once we have call site specific value information we can provide
+    //       call site specific liveness liveness information and then it makes
+    //       sense to specialize attributes for call sites instead of
+    //       redirecting requests to the callee.
+    llvm_unreachable("Abstract attributes for returned values are not "
+                     "supported for call sites yet!");
+  }
+
+  /// See AbstractAttribute::updateImpl(...).
+  ChangeStatus updateImpl(Attributor &A) override {
+    return indicatePessimisticFixpoint();
+  }
+
+  /// See AbstractAttribute::trackStatistics()
+  void trackStatistics() const override {}
+};
 
 /// ------------------------ NoSync Function Attribute -------------------------
 
@@ -1929,12 +1957,27 @@ ChangeStatus AAIsDeadImpl::updateImpl(Attributor &A) {
 }
 
 /// Liveness information for a call sites.
-//
-// TODO: Once we have call site specific value information we can provide call
-//       site specific liveness liveness information and then it makes sense to
-//       specialize attributes for call sites instead of redirecting requests to
-//       the callee.
-using AAIsDeadCallSite = AAIsDeadFunction;
+struct AAIsDeadCallSite final : AAIsDeadImpl {
+  AAIsDeadCallSite(const IRPosition &IRP) : AAIsDeadImpl(IRP) {}
+
+  /// See AbstractAttribute::initialize(...).
+  void initialize(Attributor &A) override {
+    // TODO: Once we have call site specific value information we can provide
+    //       call site specific liveness liveness information and then it makes
+    //       sense to specialize attributes for call sites instead of
+    //       redirecting requests to the callee.
+    llvm_unreachable("Abstract attributes for liveness are not "
+                     "supported for call sites yet!");
+  }
+
+  /// See AbstractAttribute::updateImpl(...).
+  ChangeStatus updateImpl(Attributor &A) override {
+    return indicatePessimisticFixpoint();
+  }
+
+  /// See AbstractAttribute::trackStatistics()
+  void trackStatistics() const override {}
+};
 
 /// -------------------- Dereferenceable Argument Attribute --------------------
 
@@ -2385,7 +2428,8 @@ bool Attributor::checkForAllReturnedValuesAndReturnInsts(
 
   // If this is a call site query we use the call site specific return values
   // and liveness information.
-  const IRPosition &QueryIRP = IRPosition::function_scope(IRP);
+  // TODO: use the function scope once we have call site AAReturnedValues.
+  const IRPosition &QueryIRP = IRPosition::function(*AssociatedFunction);
   const auto &AARetVal = getAAFor<AAReturnedValues>(QueryingAA, QueryIRP);
   if (!AARetVal.getState().isValidState())
     return false;
@@ -2402,7 +2446,8 @@ bool Attributor::checkForAllReturnedValues(
   if (!AssociatedFunction || !AssociatedFunction->hasExactDefinition())
     return false;
 
-  const IRPosition &QueryIRP = IRPosition::function_scope(IRP);
+  // TODO: use the function scope once we have call site AAReturnedValues.
+  const IRPosition &QueryIRP = IRPosition::function(*AssociatedFunction);
   const auto &AARetVal = getAAFor<AAReturnedValues>(QueryingAA, QueryIRP);
   if (!AARetVal.getState().isValidState())
     return false;
@@ -2423,7 +2468,8 @@ bool Attributor::checkForAllInstructions(
   if (!AssociatedFunction || !AssociatedFunction->hasExactDefinition())
     return false;
 
-  const IRPosition &QueryIRP = IRPosition::function_scope(IRP);
+  // TODO: use the function scope once we have call site AAReturnedValues.
+  const IRPosition &QueryIRP = IRPosition::function(*AssociatedFunction);
   const auto &LivenessAA =
       getAAFor<AAIsDead>(QueryingAA, QueryIRP, /* TrackDependence */ false);
   bool AnyDead = false;
@@ -2459,8 +2505,10 @@ bool Attributor::checkForAllReadWriteInstructions(
   if (!AssociatedFunction)
     return false;
 
-  const auto &LivenessAA = getAAFor<AAIsDead>(
-      QueryingAA, QueryingAA.getIRPosition(), /* TrackDependence */ false);
+  // TODO: use the function scope once we have call site AAReturnedValues.
+  const IRPosition &QueryIRP = IRPosition::function(*AssociatedFunction);
+  const auto &LivenessAA =
+      getAAFor<AAIsDead>(QueryingAA, QueryIRP, /* TrackDependence */ false);
   bool AnyDead = false;
 
   for (Instruction *I :

diff --git a/test/Transforms/FunctionAttrs/align.ll b/test/Transforms/FunctionAttrs/align.ll
index 0531ca729d98f3691f0a62c4775a56d03fdc5230..fd387911386874ed9645fb14b23ae01e49006bdc 100644 (file)
--- a/test/Transforms/FunctionAttrs/align.ll
+++ b/test/Transforms/FunctionAttrs/align.ll
@@ -1,4 +1,4 @@
-; RUN: opt -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=17 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
+; RUN: opt -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=15 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 

diff --git a/test/Transforms/FunctionAttrs/arg_nocapture.ll b/test/Transforms/FunctionAttrs/arg_nocapture.ll
index ffa0fe5d346029972273dba4a95401405fb1c7bb..5905575c820c1d47243b989c98368eddd1b3192f 100644 (file)
--- a/test/Transforms/FunctionAttrs/arg_nocapture.ll
+++ b/test/Transforms/FunctionAttrs/arg_nocapture.ll
@@ -1,4 +1,4 @@
-; RUN: opt -functionattrs -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=18 -S < %s | FileCheck %s
+; RUN: opt -functionattrs -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=16 -S < %s | FileCheck %s
 ;
 ; Test cases specifically designed for the "no-capture" argument attribute.
 ; We use FIXME's to indicate problems and missing attributes.

diff --git a/test/Transforms/FunctionAttrs/arg_returned.ll b/test/Transforms/FunctionAttrs/arg_returned.ll
index 9ea95e20ca13451b336021a73471940e2d39bb17..9a4cc4d68ec43715f81543f5a96b1b9f2ec55e2f 100644 (file)
--- a/test/Transforms/FunctionAttrs/arg_returned.ll
+++ b/test/Transforms/FunctionAttrs/arg_returned.ll
@@ -1,5 +1,5 @@
 ; RUN: opt -functionattrs -S < %s | FileCheck %s --check-prefix=FNATTR
-; RUN: opt -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=26 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
+; RUN: opt -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=22 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
 ; RUN: opt -attributor -attributor-disable=false -functionattrs -S < %s | FileCheck %s --check-prefix=BOTH
 ;
 ; Test cases specifically designed for the "returned" argument attribute.

diff --git a/test/Transforms/FunctionAttrs/liveness.ll b/test/Transforms/FunctionAttrs/liveness.ll
index 54bb9eac6280b90d85c732e133801e7f57ea4698..7dc392c674d16e6f5c887065bbc628432c3d6447 100644 (file)
--- a/test/Transforms/FunctionAttrs/liveness.ll
+++ b/test/Transforms/FunctionAttrs/liveness.ll
@@ -1,4 +1,4 @@
-; RUN: opt -attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=6 -S < %s | FileCheck %s
+; RUN: opt -attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=7 -S < %s | FileCheck %s
 
 declare void @no_return_call() nofree noreturn nounwind readnone
 

diff --git a/test/Transforms/FunctionAttrs/nonnull.ll b/test/Transforms/FunctionAttrs/nonnull.ll
index 1022b7c5437c7095deb18f181c9c8aabdd0c2275..e7fbb9194d30e09827fa4d61133089cbea5f19c5 100644 (file)
--- a/test/Transforms/FunctionAttrs/nonnull.ll
+++ b/test/Transforms/FunctionAttrs/nonnull.ll
@@ -1,6 +1,6 @@
 ; RUN: opt -S -functionattrs -enable-nonnull-arg-prop %s | FileCheck %s --check-prefixes=BOTH,FNATTR
 ; RUN: opt -S -passes=function-attrs -enable-nonnull-arg-prop %s | FileCheck %s --check-prefixes=BOTH,FNATTR
-; RUN: opt -attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=12 -S < %s | FileCheck %s --check-prefixes=BOTH,ATTRIBUTOR
+; RUN: opt -attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=11 -S < %s | FileCheck %s --check-prefixes=BOTH,ATTRIBUTOR
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 

diff --git a/test/Transforms/FunctionAttrs/nounwind.ll b/test/Transforms/FunctionAttrs/nounwind.ll
index 66f23598b4e5498efc3ede94937799af1d38f173..c2c30f0fe38ec64e41f96ef39700e2f12bdb0637 100644 (file)
--- a/test/Transforms/FunctionAttrs/nounwind.ll
+++ b/test/Transforms/FunctionAttrs/nounwind.ll
@@ -1,5 +1,5 @@
 ; RUN: opt < %s -functionattrs -S | FileCheck %s
-; RUN: opt < %s -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=12 -S | FileCheck %s --check-prefix=ATTRIBUTOR
+; RUN: opt < %s -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=10 -S | FileCheck %s --check-prefix=ATTRIBUTOR
 
 ; TEST 1
 ; CHECK: Function Attrs: norecurse nounwind readnone

diff --git a/test/Transforms/FunctionAttrs/read_write_returned_arguments_scc.ll b/test/Transforms/FunctionAttrs/read_write_returned_arguments_scc.ll
index ed16ac8fcbf36d23c22a8823cf0115e5cb312550..d95dd2d028d5461f2394597dcae32ea642935cde 100644 (file)
--- a/test/Transforms/FunctionAttrs/read_write_returned_arguments_scc.ll
+++ b/test/Transforms/FunctionAttrs/read_write_returned_arguments_scc.ll
@@ -1,4 +1,4 @@
-; RUN: opt -functionattrs -enable-nonnull-arg-prop -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=28 -S < %s | FileCheck %s
+; RUN: opt -functionattrs -enable-nonnull-arg-prop -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=21 -S < %s | FileCheck %s
 ;
 ; This is an evolved example to stress test SCC parameter attribute propagation.
 ; The SCC in this test is made up of the following six function, three of which