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[FuncSpec] Allow ConstExprs that are function pointers

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This is a follow up of D110529 that disallowed constexprs. That change
introduced a regression as this also disallowed constexprs that are function
pointers, which is actually one of the motivating use cases that we do want to
support.

Differential Revision: https://reviews.llvm.org/D111567
This commit is contained in:
Sjoerd Meijer 2021-10-12 11:03:34 +01:00
parent cd0ba9dc58
commit fc0fa85171
2 changed files with 35 additions and 2 deletions
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8
llvm/lib/Transforms/IPO/FunctionSpecialization.cpp
View File

@ -677,8 +677,12 @@ private:
auto *V = CS.getArgOperand(A->getArgNo());
if (isa<PoisonValue>(V))
return false;
if (isa<ConstantExpr>(V))
return false;
// For now, constant expressions are fine but only if they are function
// calls.
if (auto *CE = dyn_cast<ConstantExpr>(V))
if (!isa<Function>(CE->getOperand(0)))
return false;
// TrackValueOfGlobalVariable only tracks scalar global variables.
if (auto *GV = dyn_cast<GlobalVariable>(V)) {

29
llvm/test/Transforms/FunctionSpecialization/function-specialization-constant-expression3.ll Normal file
View File

@ -0,0 +1,29 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -function-specialization -force-function-specialization -S < %s | FileCheck %s
define i32 @main() {
; CHECK-LABEL: @main(
; CHECK-NEXT: bb:
; CHECK-NEXT: tail call void @wombat.1(i8* undef, i64 undef, i64 undef, i32 (i8*, i8*)* bitcast (i32 ()* @quux to i32 (i8*, i8*)*))
; CHECK-NEXT: tail call void @wombat.2(i8* undef, i64 undef, i64 undef, i32 (i8*, i8*)* bitcast (i32 ()* @eggs to i32 (i8*, i8*)*))
; CHECK-NEXT: ret i32 undef
;
bb:
tail call void @wombat(i8* undef, i64 undef, i64 undef, i32 (i8*, i8*)* bitcast (i32 ()* @quux to i32 (i8*, i8*)*))
tail call void @wombat(i8* undef, i64 undef, i64 undef, i32 (i8*, i8*)* bitcast (i32 ()* @eggs to i32 (i8*, i8*)*))
ret i32 undef
}
declare i32 @quux()
declare i32 @eggs()
define internal void @wombat(i8* %arg, i64 %arg1, i64 %arg2, i32 (i8*, i8*)* %arg3) {
; CHECK-LABEL: @wombat(
; CHECK-NEXT: bb4:
; CHECK-NEXT: [[TMP:%.*]] = tail call i32 [[ARG3:%.*]](i8* undef, i8* undef)
; CHECK-NEXT: ret void
;
bb4:
%tmp = tail call i32 %arg3(i8* undef, i8* undef)
ret void
}