[llvm] c0ad1b4 - [NewGVN] Fold equivalent freeze instructions

[Jay Foad via llvm-commits]

Author: Jay Foad
Date: 2023-06-09T20:57:36+01:00
New Revision: c0ad1b459742117990d38186deaeb49e75bb26f3

URL: https://github.com/llvm/llvm-project/commit/c0ad1b459742117990d38186deaeb49e75bb26f3
DIFF: https://github.com/llvm/llvm-project/commit/c0ad1b459742117990d38186deaeb49e75bb26f3.diff

LOG: [NewGVN] Fold equivalent freeze instructions

Differential Revision: https://reviews.llvm.org/D152529

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/NewGVN.cpp
    llvm/test/Transforms/NewGVN/freeze.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Scalar/NewGVN.cpp b/llvm/lib/Transforms/Scalar/NewGVN.cpp
index 3de55759ed3a0..12dd161fb788e 100644
--- a/llvm/lib/Transforms/Scalar/NewGVN.cpp
+++ b/llvm/lib/Transforms/Scalar/NewGVN.cpp
@@ -1994,6 +1994,7 @@ NewGVN::performSymbolicEvaluation(Value *V,
       break;
     case Instruction::BitCast:
     case Instruction::AddrSpaceCast:
+    case Instruction::Freeze:
       return createExpression(I);
       break;
     case Instruction::ICmp:

diff  --git a/llvm/test/Transforms/NewGVN/freeze.ll b/llvm/test/Transforms/NewGVN/freeze.ll
index d96580f49d9fc..d775736f0f187 100644
--- a/llvm/test/Transforms/NewGVN/freeze.ll
+++ b/llvm/test/Transforms/NewGVN/freeze.ll
@@ -4,9 +4,7 @@
 define i1 @f(i1 %a) {
 ; CHECK-LABEL: @f(
 ; CHECK-NEXT:    [[B:%.*]] = freeze i1 [[A:%.*]]
-; CHECK-NEXT:    [[C:%.*]] = freeze i1 [[A]]
-; CHECK-NEXT:    [[D:%.*]] = and i1 [[B]], [[C]]
-; CHECK-NEXT:    ret i1 [[D]]
+; CHECK-NEXT:    ret i1 [[B]]
 ;
   %b = freeze i1 %a
   %c = freeze i1 %a
@@ -17,10 +15,9 @@ define i1 @f(i1 %a) {
 define void @f_multipleuses(i1 %a) {
 ; CHECK-LABEL: @f_multipleuses(
 ; CHECK-NEXT:    [[B:%.*]] = freeze i1 [[A:%.*]]
-; CHECK-NEXT:    [[C:%.*]] = freeze i1 [[A]]
 ; CHECK-NEXT:    call void @use1(i1 [[B]])
-; CHECK-NEXT:    call void @use1(i1 [[C]])
-; CHECK-NEXT:    call void @use1(i1 [[C]])
+; CHECK-NEXT:    call void @use1(i1 [[B]])
+; CHECK-NEXT:    call void @use1(i1 [[B]])
 ; CHECK-NEXT:    ret void
 ;
   %b = freeze i1 %a