[IndVarSimplify] Add tests for saturating math on IV; NFC

These saturating math ops can be replaced with simple math.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362320 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Transforms/IndVarSimplify/eliminate-sat.ll b/test/Transforms/IndVarSimplify/eliminate-sat.ll
new file mode 100644 (file)
index 0000000..b7c3804
--- /dev/null
+++ b/test/Transforms/IndVarSimplify/eliminate-sat.ll
@@ -0,0 +1,123 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -S -indvars | FileCheck %s
+
+declare i32 @llvm.uadd.sat.i32(i32, i32)
+declare i32 @llvm.sadd.sat.i32(i32, i32)
+declare i32 @llvm.usub.sat.i32(i32, i32)
+declare i32 @llvm.ssub.sat.i32(i32, i32)
+
+define void @uadd_sat(i32* %p) {
+; CHECK-LABEL: @uadd_sat(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[I_INC:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[SAT:%.*]] = call i32 @llvm.uadd.sat.i32(i32 [[I]], i32 1)
+; CHECK-NEXT:    store volatile i32 [[SAT]], i32* [[P:%.*]]
+; CHECK-NEXT:    [[I_INC]] = add nuw nsw i32 [[I]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i32 [[I_INC]], 100
+; CHECK-NEXT:    br i1 [[CMP]], label [[LOOP]], label [[END:%.*]]
+; CHECK:       end:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %loop
+
+loop:
+  %i = phi i32 [ 0, %entry ], [ %i.inc, %loop ]
+  %sat = call i32 @llvm.uadd.sat.i32(i32 %i, i32 1)
+  store volatile i32 %sat, i32* %p
+  %i.inc = add nuw nsw i32 %i, 1
+  %cmp = icmp ne i32 %i.inc, 100
+  br i1 %cmp, label %loop, label %end
+
+end:
+  ret void
+}
+
+define void @sadd_sat(i32* %p) {
+; CHECK-LABEL: @sadd_sat(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[I_INC:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[SAT:%.*]] = call i32 @llvm.sadd.sat.i32(i32 [[I]], i32 1)
+; CHECK-NEXT:    store volatile i32 [[SAT]], i32* [[P:%.*]]
+; CHECK-NEXT:    [[I_INC]] = add nuw nsw i32 [[I]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i32 [[I_INC]], 100
+; CHECK-NEXT:    br i1 [[CMP]], label [[LOOP]], label [[END:%.*]]
+; CHECK:       end:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %loop
+
+loop:
+  %i = phi i32 [ 0, %entry ], [ %i.inc, %loop ]
+  %sat = call i32 @llvm.sadd.sat.i32(i32 %i, i32 1)
+  store volatile i32 %sat, i32* %p
+  %i.inc = add nuw nsw i32 %i, 1
+  %cmp = icmp ne i32 %i.inc, 100
+  br i1 %cmp, label %loop, label %end
+
+end:
+  ret void
+}
+
+define void @usub_sat(i32* %p) {
+; CHECK-LABEL: @usub_sat(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 1, [[ENTRY:%.*]] ], [ [[I_INC:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[SAT:%.*]] = call i32 @llvm.usub.sat.i32(i32 [[I]], i32 1)
+; CHECK-NEXT:    store volatile i32 [[SAT]], i32* [[P:%.*]]
+; CHECK-NEXT:    [[I_INC]] = add nuw nsw i32 [[I]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i32 [[I_INC]], 100
+; CHECK-NEXT:    br i1 [[CMP]], label [[LOOP]], label [[END:%.*]]
+; CHECK:       end:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %loop
+
+loop:
+  %i = phi i32 [ 1, %entry ], [ %i.inc, %loop ]
+  %sat = call i32 @llvm.usub.sat.i32(i32 %i, i32 1)
+  store volatile i32 %sat, i32* %p
+  %i.inc = add nuw nsw i32 %i, 1
+  %cmp = icmp ne i32 %i.inc, 100
+  br i1 %cmp, label %loop, label %end
+
+end:
+  ret void
+}
+
+define void @ssub_sat(i32* %p) {
+; CHECK-LABEL: @ssub_sat(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[I_INC:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[SAT:%.*]] = call i32 @llvm.ssub.sat.i32(i32 [[I]], i32 1)
+; CHECK-NEXT:    store volatile i32 [[SAT]], i32* [[P:%.*]]
+; CHECK-NEXT:    [[I_INC]] = add nuw nsw i32 [[I]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i32 [[I_INC]], 100
+; CHECK-NEXT:    br i1 [[CMP]], label [[LOOP]], label [[END:%.*]]
+; CHECK:       end:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %loop
+
+loop:
+  %i = phi i32 [ 0, %entry ], [ %i.inc, %loop ]
+  %sat = call i32 @llvm.ssub.sat.i32(i32 %i, i32 1)
+  store volatile i32 %sat, i32* %p
+  %i.inc = add nuw nsw i32 %i, 1
+  %cmp = icmp ne i32 %i.inc, 100
+  br i1 %cmp, label %loop, label %end
+
+end:
+  ret void
+}