[PATCH] D75398: [GVN] Fold equivalent freeze instructions

[Juneyoung Lee via Phabricator via llvm-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rG5cbb26569474: [GVN] Fold equivalent freeze instructions (authored by aqjune).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D75398/new/

https://reviews.llvm.org/D75398

Files:
  llvm/lib/Transforms/Scalar/GVN.cpp
  llvm/test/Transforms/GVN/freeze.ll


Index: llvm/test/Transforms/GVN/freeze.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/GVN/freeze.ll
@@ -0,0 +1,56 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -gvn -S | FileCheck %s
+; RUN: opt < %s -passes=gvn -S | FileCheck %s
+
+define i1 @f(i1 %a) {
+; CHECK-LABEL: @f(
+; CHECK-NEXT:    [[B:%.*]] = freeze i1 [[A:%.*]]
+; CHECK-NEXT:    ret i1 [[B]]
+;
+  %b = freeze i1 %a
+  %c = freeze i1 %a
+  %d = and i1 %b, %b
+  ret i1 %d
+}
+
+define void @f_multipleuses(i1 %a) {
+; CHECK-LABEL: @f_multipleuses(
+; CHECK-NEXT:    [[B:%.*]] = freeze i1 [[A:%.*]]
+; CHECK-NEXT:    call void @use1(i1 [[B]])
+; CHECK-NEXT:    call void @use1(i1 [[B]])
+; CHECK-NEXT:    call void @use1(i1 [[B]])
+; CHECK-NEXT:    ret void
+;
+  %b = freeze i1 %a
+  %c = freeze i1 %a
+  call void @use1(i1 %b)
+  call void @use1(i1 %c)
+  call void @use1(i1 %c)
+  ret void
+}
+
+define void @f_dom(i1 %cond, i1 %a) {
+; CHECK-LABEL: @f_dom(
+; CHECK-NEXT:    br i1 [[COND:%.*]], label [[BB1:%.*]], label [[BB2:%.*]]
+; CHECK:       BB1:
+; CHECK-NEXT:    [[X:%.*]] = freeze i1 [[A:%.*]]
+; CHECK-NEXT:    call void @use1(i1 [[X]])
+; CHECK-NEXT:    ret void
+; CHECK:       BB2:
+; CHECK-NEXT:    [[Y:%.*]] = freeze i1 [[A]]
+; CHECK-NEXT:    call void @use2(i1 [[Y]])
+; CHECK-NEXT:    ret void
+;
+  br i1 %cond, label %BB1, label %BB2
+BB1:
+  %x = freeze i1 %a
+  call void @use1(i1 %x)
+  ret void
+BB2:
+  %y = freeze i1 %a
+  call void @use2(i1 %y) ; cannot use %x
+  ret void
+}
+declare void @use1(i1)
+declare void @use2(i1)
+
Index: llvm/lib/Transforms/Scalar/GVN.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/GVN.cpp
+++ llvm/lib/Transforms/Scalar/GVN.cpp
@@ -531,6 +531,7 @@
     case Instruction::AddrSpaceCast:
     case Instruction::BitCast:
     case Instruction::Select:
+    case Instruction::Freeze:
     case Instruction::ExtractElement:
     case Instruction::InsertElement:
     case Instruction::ShuffleVector:


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D75398.247465.patch
Type: text/x-patch
Size: 2087 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20200229/e59fbfcb/attachment.bin>