[llvm] 30c9d68 - [Attributor][FIX] Arguments of unknown functions can be undef
Johannes Doerfert via llvm-commits
llvm-commits at lists.llvm.org
Thu Jun 17 23:10:56 PDT 2021
Author: Johannes Doerfert
Date: 2021-06-18T01:07:53-05:00
New Revision: 30c9d68ad93af7f420f6d01f91adf12ff36254a0
URL: https://github.com/llvm/llvm-project/commit/30c9d68ad93af7f420f6d01f91adf12ff36254a0
DIFF: https://github.com/llvm/llvm-project/commit/30c9d68ad93af7f420f6d01f91adf12ff36254a0.diff
LOG: [Attributor][FIX] Arguments of unknown functions can be undef
This should fix PR50683. The wrong assumption was that we
could always know what the callee is when we replace a call site
argument with undef. We wanted to know that to remove the `noundef`
that might be attached to the argument. Since no callee means we
did the propagation on the caller site, there is no need to remove
an attribute. It is only needed if we replace all uses and therefore
pass `undef` instead of the value that was passed in otherwise.
Added:
Modified:
llvm/lib/Transforms/IPO/Attributor.cpp
llvm/test/Transforms/Attributor/value-simplify.ll
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/IPO/Attributor.cpp b/llvm/lib/Transforms/IPO/Attributor.cpp
index 8d42519cd761..957157d28bc7 100644
--- a/llvm/lib/Transforms/IPO/Attributor.cpp
+++ b/llvm/lib/Transforms/IPO/Attributor.cpp
@@ -1358,8 +1358,7 @@ ChangeStatus Attributor::cleanupIR() {
unsigned Idx = CB->getArgOperandNo(U);
CB->removeParamAttr(Idx, Attribute::NoUndef);
Function *Fn = CB->getCalledFunction();
- assert(Fn && "Expected callee when call argument is replaced!");
- if (Fn->arg_size() > Idx)
+ if (Fn && Fn->arg_size() > Idx)
Fn->removeParamAttr(Idx, Attribute::NoUndef);
}
}
diff --git a/llvm/test/Transforms/Attributor/value-simplify.ll b/llvm/test/Transforms/Attributor/value-simplify.ll
index 36016eb25360..db4b8b6ef88f 100644
--- a/llvm/test/Transforms/Attributor/value-simplify.ll
+++ b/llvm/test/Transforms/Attributor/value-simplify.ll
@@ -14,6 +14,7 @@ declare i8* @llvm.call.preallocated.arg(token, i32)
;.
; CHECK: @[[CONSTAS3PTR:[a-zA-Z0-9_$"\\.-]+]] = addrspace(3) global i32 0, align 4
; CHECK: @[[S:[a-zA-Z0-9_$"\\.-]+]] = external global [[STRUCT_X:%.*]]
+; CHECK: @[[G:[a-zA-Z0-9_$"\\.-]+]] = internal constant { [2 x i8*] } { [2 x i8*] [i8* bitcast (void (i8***)* @f1 to i8*), i8* bitcast (void (i1 (i8*)*)* @f2 to i8*)] }
;.
define internal i32 addrspace(3)* @const_ptr_return_as3() {
; IS__CGSCC____: Function Attrs: nofree norecurse nosync nounwind readnone willreturn
@@ -1086,6 +1087,129 @@ define i1 @icmp() {
%c = icmp eq i8* null, null
ret i1 %c
}
+
+define void @test_callee_is_undef(void (i32)* %fn) {
+; IS__TUNIT____-LABEL: define {{[^@]+}}@test_callee_is_undef
+; IS__TUNIT____-SAME: (void (i32)* nocapture nofree [[FN:%.*]]) {
+; IS__TUNIT____-NEXT: call void @callee_is_undef()
+; IS__TUNIT____-NEXT: call void @unknown_calle_arg_is_undef(void (i32)* nocapture nofree [[FN]], i32 undef)
+; IS__TUNIT____-NEXT: ret void
+;
+; IS__CGSCC____-LABEL: define {{[^@]+}}@test_callee_is_undef
+; IS__CGSCC____-SAME: (void (i32)* nocapture nofree [[FN:%.*]]) {
+; IS__CGSCC____-NEXT: unreachable
+;
+ call void @callee_is_undef(void ()* undef)
+ call void @unknown_calle_arg_is_undef(void (i32)* %fn, i32 undef)
+ ret void
+}
+define internal void @callee_is_undef(void ()* %fn) {
+;
+; IS__TUNIT____-LABEL: define {{[^@]+}}@callee_is_undef() {
+; IS__TUNIT____-NEXT: call void undef()
+; IS__TUNIT____-NEXT: ret void
+;
+; IS__CGSCC____-LABEL: define {{[^@]+}}@callee_is_undef
+; IS__CGSCC____-SAME: (void ()* noalias nocapture nofree noundef nonnull [[FN:%.*]]) {
+; IS__CGSCC____-NEXT: call void [[FN]]()
+; IS__CGSCC____-NEXT: ret void
+;
+ call void %fn()
+ ret void
+}
+define internal void @unknown_calle_arg_is_undef(void (i32)* %fn, i32 %arg) {
+;
+; IS__TUNIT____-LABEL: define {{[^@]+}}@unknown_calle_arg_is_undef
+; IS__TUNIT____-SAME: (void (i32)* nocapture nofree noundef nonnull [[FN:%.*]], i32 [[ARG:%.*]]) {
+; IS__TUNIT____-NEXT: call void [[FN]](i32 undef)
+; IS__TUNIT____-NEXT: ret void
+;
+; IS__CGSCC____-LABEL: define {{[^@]+}}@unknown_calle_arg_is_undef
+; IS__CGSCC____-SAME: (void (i32)* nocapture nofree noundef nonnull [[FN:%.*]]) {
+; IS__CGSCC____-NEXT: call void [[FN]](i32 undef)
+; IS__CGSCC____-NEXT: ret void
+;
+ call void %fn(i32 %arg)
+ ret void
+}
+
+; Taken from 50683
+; {{{
+
+ at g = internal constant { [2 x i8*] } { [2 x i8*] [i8* bitcast (void (i8***)* @f1 to i8*), i8* bitcast (void (i1 (i8*)*)* @f2 to i8*)] }
+
+define internal void @f1(i8*** %a) {
+; IS__TUNIT____: Function Attrs: argmemonly nofree nosync nounwind willreturn writeonly
+; IS__TUNIT____-LABEL: define {{[^@]+}}@f1
+; IS__TUNIT____-SAME: (i8*** nocapture nofree noundef nonnull writeonly align 8 dereferenceable(8) [[A:%.*]]) #[[ATTR3]] {
+; IS__TUNIT____-NEXT: entry:
+; IS__TUNIT____-NEXT: [[X:%.*]] = getelementptr { [2 x i8*] }, { [2 x i8*] }* @g, i32 0, i32 0, i32 0
+; IS__TUNIT____-NEXT: store i8** [[X]], i8*** [[A]], align 8
+; IS__TUNIT____-NEXT: ret void
+;
+; IS__CGSCC____: Function Attrs: argmemonly nofree norecurse nosync nounwind willreturn writeonly
+; IS__CGSCC____-LABEL: define {{[^@]+}}@f1
+; IS__CGSCC____-SAME: (i8*** nocapture nofree noundef nonnull writeonly align 8 dereferenceable(8) [[A:%.*]]) #[[ATTR2]] {
+; IS__CGSCC____-NEXT: entry:
+; IS__CGSCC____-NEXT: [[X:%.*]] = getelementptr { [2 x i8*] }, { [2 x i8*] }* @g, i32 0, i32 0, i32 0
+; IS__CGSCC____-NEXT: store i8** [[X]], i8*** [[A]], align 8
+; IS__CGSCC____-NEXT: ret void
+;
+entry:
+ %x = getelementptr { [2 x i8*] }, { [2 x i8*] }* @g, i32 0, i32 0, i32 0
+ store i8** %x , i8*** %a, align 8
+ ret void
+}
+
+define internal void @f2(i1 (i8*)* %a) {
+; CHECK-LABEL: define {{[^@]+}}@f2
+; CHECK-SAME: (i1 (i8*)* [[A:%.*]]) {
+; CHECK-NEXT: cont461:
+; CHECK-NEXT: [[C1:%.*]] = bitcast i1 (i8*)* [[A]] to i8*
+; CHECK-NEXT: call void @f3(i8* [[C1]], i1 (i8*)* nocapture nofree [[A]])
+; CHECK-NEXT: ret void
+;
+cont461:
+ %c1 = bitcast i1 (i8*)* %a to i8*
+ call void @f3(i8* %c1, i1 (i8*)* %a)
+ ret void
+}
+
+define internal void @f3(i8* %a1, i1 (i8*)* %a) {
+; CHECK-LABEL: define {{[^@]+}}@f3
+; CHECK-SAME: (i8* [[A1:%.*]], i1 (i8*)* nocapture nofree [[A:%.*]]) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[CALL20:%.*]] = call i1 @f9()
+; CHECK-NEXT: br i1 [[CALL20]], label [[LAND_LHS_TRUE:%.*]], label [[IF_END40:%.*]]
+; CHECK: land.lhs.true:
+; CHECK-NEXT: [[TMP0:%.*]] = call i1 [[A]](i8* [[A1]])
+; CHECK-NEXT: br label [[IF_END40]]
+; CHECK: if.end40:
+; CHECK-NEXT: ret void
+;
+entry:
+ %call20 = call i1 @f9()
+ br i1 %call20, label %land.lhs.true, label %if.end40
+
+land.lhs.true:
+ call i1 %a(i8* %a1)
+ br label %if.end40
+
+if.end40:
+ ret void
+}
+
+define linkonce_odr i1 @f9() {
+; CHECK-LABEL: define {{[^@]+}}@f9() {
+; CHECK-NEXT: entry:
+; CHECK-NEXT: ret i1 false
+;
+entry:
+ ret i1 false
+}
+
+; }}}
+
;.
; IS__TUNIT_OPM: attributes #[[ATTR0]] = { nofree nosync nounwind willreturn }
; IS__TUNIT_OPM: attributes #[[ATTR1]] = { nofree nosync nounwind readnone willreturn }
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