[PATCH] D90391: [gvn] PRE needs to skip convergent intrinsics/calls.

[Michael Liao via Phabricator via llvm-commits]

hliao updated this revision to Diff 301900.
hliao added a comment.

Revise the test following reviewers' comments.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D90391/new/

https://reviews.llvm.org/D90391

Files:
  llvm/lib/Transforms/Scalar/GVN.cpp
  llvm/test/Transforms/GVN/pre-skip-convergent.ll


Index: llvm/test/Transforms/GVN/pre-skip-convergent.ll
===================================================================
--- llvm/test/Transforms/GVN/pre-skip-convergent.ll
+++ llvm/test/Transforms/GVN/pre-skip-convergent.ll
@@ -1,5 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt -S -gvn -o - %s | FileCheck %s
+; RUN: opt -S -passes=gvn -o - %s | FileCheck %s
 
 define i32 @foo(i1 %cond, i32* %q, i32* %p) {
 ; CHECK-LABEL: @foo(
@@ -9,12 +10,11 @@
 ; CHECK-NEXT:    br i1 [[COND:%.*]], label [[PRE:%.*]], label [[MERGE:%.*]]
 ; CHECK:       pre:
 ; CHECK-NEXT:    [[T0:%.*]] = load i32, i32* [[P:%.*]], align 4
-; CHECK-NEXT:    [[DOTPRE:%.*]] = call i32 @llvm.convergent(i32 [[T0]])
 ; CHECK-NEXT:    br label [[MERGE]]
 ; CHECK:       merge:
-; CHECK-NEXT:    [[R0_PRE_PHI:%.*]] = phi i32 [ [[DOTPRE]], [[PRE]] ], [ [[V0]], [[ENTRY:%.*]] ]
-; CHECK-NEXT:    [[M0:%.*]] = phi i32 [ [[T0]], [[PRE]] ], [ 0, [[ENTRY]] ]
-; CHECK-NEXT:    ret i32 [[R0_PRE_PHI]]
+; CHECK-NEXT:    [[M0:%.*]] = phi i32 [ [[T0]], [[PRE]] ], [ 0, [[ENTRY:%.*]] ]
+; CHECK-NEXT:    [[R0:%.*]] = call i32 @llvm.convergent(i32 [[M0]])
+; CHECK-NEXT:    ret i32 [[R0]]
 ;
 entry:
   %v0 = call i32 @llvm.convergent(i32 0)
Index: llvm/lib/Transforms/Scalar/GVN.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/GVN.cpp
+++ llvm/lib/Transforms/Scalar/GVN.cpp
@@ -2460,10 +2460,14 @@
   if (isa<GetElementPtrInst>(CurInst))
     return false;
 
-  // We don't currently value number ANY inline asm calls.
-  if (auto *CallB = dyn_cast<CallBase>(CurInst))
+  if (auto *CallB = dyn_cast<CallBase>(CurInst)) {
+    // We don't currently value number ANY inline asm calls.
     if (CallB->isInlineAsm())
       return false;
+    // Don't do PRE on convergent calls.
+    if (CallB->isConvergent())
+      return false;
+  }
 
   uint32_t ValNo = VN.lookup(CurInst);
 


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