[PATCH] D150974: [GVN] Do not combine convergent calls in GVN/NewGVN
Jay Foad via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Fri May 19 13:29:47 PDT 2023
This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rGc86a1e6903e9: [GVN] Do not combine convergent calls in GVN/NewGVN (authored by foad).
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D150974/new/
https://reviews.llvm.org/D150974
Files:
llvm/lib/Transforms/Scalar/GVN.cpp
llvm/lib/Transforms/Scalar/NewGVN.cpp
llvm/test/Transforms/GVN/convergent.ll
llvm/test/Transforms/NewGVN/convergent.ll
Index: llvm/test/Transforms/NewGVN/convergent.ll
===================================================================
--- llvm/test/Transforms/NewGVN/convergent.ll
+++ llvm/test/Transforms/NewGVN/convergent.ll
@@ -7,9 +7,11 @@
; CHECK-NEXT: [[V0:%.*]] = call i32 @llvm.convergent()
; CHECK-NEXT: br i1 [[COND:%.*]], label [[BODY:%.*]], label [[END:%.*]]
; CHECK: body:
+; CHECK-NEXT: [[V1:%.*]] = call i32 @llvm.convergent()
; CHECK-NEXT: br label [[END]]
; CHECK: end:
-; CHECK-NEXT: ret i32 [[V0]]
+; CHECK-NEXT: [[RET:%.*]] = phi i32 [ [[V0]], [[ENTRY:%.*]] ], [ [[V1]], [[BODY]] ]
+; CHECK-NEXT: ret i32 [[RET]]
;
entry:
%v0 = call i32 @llvm.convergent()
Index: llvm/test/Transforms/GVN/convergent.ll
===================================================================
--- llvm/test/Transforms/GVN/convergent.ll
+++ llvm/test/Transforms/GVN/convergent.ll
@@ -7,9 +7,11 @@
; CHECK-NEXT: [[V0:%.*]] = call i32 @llvm.convergent()
; CHECK-NEXT: br i1 [[COND:%.*]], label [[BODY:%.*]], label [[END:%.*]]
; CHECK: body:
+; CHECK-NEXT: [[V1:%.*]] = call i32 @llvm.convergent()
; CHECK-NEXT: br label [[END]]
; CHECK: end:
-; CHECK-NEXT: ret i32 [[V0]]
+; CHECK-NEXT: [[RET:%.*]] = phi i32 [ [[V0]], [[ENTRY:%.*]] ], [ [[V1]], [[BODY]] ]
+; CHECK-NEXT: ret i32 [[RET]]
;
entry:
%v0 = call i32 @llvm.convergent()
Index: llvm/lib/Transforms/Scalar/NewGVN.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/NewGVN.cpp
+++ llvm/lib/Transforms/Scalar/NewGVN.cpp
@@ -1613,6 +1613,12 @@
if (CI->getFunction()->isPresplitCoroutine())
return ExprResult::none();
+ // Do not combine convergent calls since they implicitly depend on the set of
+ // threads that is currently executing, and they might be in different basic
+ // blocks.
+ if (CI->isConvergent())
+ return ExprResult::none();
+
if (AA->doesNotAccessMemory(CI)) {
return ExprResult::some(
createCallExpression(CI, TOPClass->getMemoryLeader()));
Index: llvm/lib/Transforms/Scalar/GVN.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/GVN.cpp
+++ llvm/lib/Transforms/Scalar/GVN.cpp
@@ -473,6 +473,14 @@
return nextValueNumber++;
}
+ // Do not combine convergent calls since they implicitly depend on the set of
+ // threads that is currently executing, and they might be in different basic
+ // blocks.
+ if (C->isConvergent()) {
+ valueNumbering[C] = nextValueNumber;
+ return nextValueNumber++;
+ }
+
if (AA->doesNotAccessMemory(C)) {
Expression exp = createExpr(C);
uint32_t e = assignExpNewValueNum(exp).first;
@@ -2781,9 +2789,6 @@
// 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);
-------------- next part --------------
A non-text attachment was scrubbed...
Name: D150974.523914.patch
Type: text/x-patch
Size: 2998 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20230519/07b9ec82/attachment.bin>
More information about the llvm-commits
mailing list