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Revert "[LICM] Hoist loads with invariant.group metadata" 

This appears to miscompile google benchmark's GetCacheSizesFromKVFS()
when compiling with -fstrict-vtable-pointers.
Runnable reproducer: https://godbolt.org/z/f9ovKqTzb
The "f.fail()" crashes with BUS error, it is compiled into testb,
and the adress it is testing is non-sensical.

This reverts commit 4c89bcadf6.
This commit is contained in:
Roman Lebedev 2021-05-08 15:42:11 +03:00
parent 4e192edb2d
commit 1acd9a1a29
No known key found for this signature in database
GPG Key ID: 083C3EBB4A1689E0
2 changed files with 0 additions and 62 deletions
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4
llvm/lib/Transforms/Scalar/LICM.cpp
View File

@ -1198,10 +1198,6 @@ bool llvm::canSinkOrHoistInst(Instruction &I, AAResults *AA, DominatorTree *DT,
if (isLoadInvariantInLoop(LI, DT, CurLoop))
return true;
// Stores with an invariant.group metadata are ok to sink/hoist.
if (LI->hasMetadata(LLVMContext::MD_invariant_group))
return true;
bool Invalidated;
if (CurAST)
Invalidated = pointerInvalidatedByLoop(MemoryLocation::get(LI), CurAST,

58
llvm/test/Transforms/LICM/invariant.group.ll
View File

@ -1,58 +0,0 @@
; RUN: opt -S < %s -passes=licm | FileCheck %s
declare i8* @llvm.launder.invariant.group.p0i8(i8* %a)
; CHECK-LABEL: define{{.*}}@f
define void @f(i32* %x) {
; CHECK: entry:
; CHECK-NOT: {{.*}}:
; CHECK: load {{.*}} !invariant.group
entry:
%x_i8 = bitcast i32* %x to i8*
%x_i8_inv = call i8* @llvm.launder.invariant.group.p0i8(i8* %x_i8)
br label %for.body
for.cond.cleanup:
ret void
for.body:
%i.04 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
%x_inv = bitcast i8* %x_i8_inv to i32*
%0 = load i32, i32* %x_inv, !invariant.group !0
call void @a(i32 %0)
%inc = add nuw nsw i32 %i.04, 1
%exitcond.not = icmp eq i32 %inc, 100
br i1 %exitcond.not, label %for.cond.cleanup, label %for.body
}
; CHECK-LABEL: define{{.*}}@g
define void @g(i32* %x) {
; CHECK: for.body:
; CHECK-NOT: {{.*}}:
; CHECK: load {{.*}} !invariant.group
entry:
%x_i8 = bitcast i32* %x to i8*
br label %for.body
for.cond.cleanup:
ret void
for.body:
%i.04 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
%x_i8_inv = call i8* @llvm.launder.invariant.group.p0i8(i8* %x_i8)
%x_inv = bitcast i8* %x_i8_inv to i32*
%0 = load i32, i32* %x_inv, !invariant.group !0
call void @a(i32 %0)
%inc = add nuw nsw i32 %i.04, 1
%exitcond.not = icmp eq i32 %inc, 100
br i1 %exitcond.not, label %for.cond.cleanup, label %for.body
}
declare void @a(i32)
!0 = !{}