replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

[FIX] Do not hoist nested variant base pointers 

This fixes bug 25249.

llvm-svn: 250958
This commit is contained in:
Johannes Doerfert 2015-10-21 22:14:57 +00:00
parent 86713d90c7
commit 654c3284f4
2 changed files with 45 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
polly/lib/Analysis/ScopInfo.cpp
View File

@ -2549,14 +2549,18 @@ void Scop::hoistInvariantLoads() {
// not loaded inside the SCoP. This can happened e.g., if a readnone call
// returns a pointer that is used as a base address. However, as we want
// to hoist indirect pointers, we allow the base pointer to be defined in
// the region if it is also a memory access. Hence, if the ScopArrayInfo
// object has a base pointer origin we know the base pointer is loaded and
// that it is invariant, thus it will be hoisted too.
// the region if it is also a memory access. Each ScopArrayInfo object
// that has a base pointer origin has a base pointer that is loaded and
// that it is invariant, thus it will be hoisted too. However, if there is
// no bease pointer origin we check that the base pointer is defined
// outside the region.
const ScopArrayInfo *SAI = MA->getScopArrayInfo();
if (!SAI->getBasePtrOriginSAI())
if (auto *BasePtrInst = dyn_cast<Instruction>(SAI->getBasePtr()))
if (R.contains(BasePtrInst))
continue;
while (auto *BasePtrOriginSAI = SAI->getBasePtrOriginSAI())
SAI = BasePtrOriginSAI;
if (auto *BasePtrInst = dyn_cast<Instruction>(SAI->getBasePtr()))
if (R.contains(BasePtrInst))
continue;
// Skip accesses in non-affine subregions as they might not be executed
// under the same condition as the entry of the non-affine subregion.

34
polly/test/ScopInfo/variant_base_pointer.ll Normal file
View File

@ -0,0 +1,34 @@
; RUN: opt %loadPolly -polly-ignore-aliasing -polly-scops -analyze < %s | FileCheck %s
; RUN: opt %loadPolly -polly-ignore-aliasing -polly-codegen -analyze < %s
;
; CHECK: Invariant Accesses: {
; CHECK-NEXT: }
;
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
; Function Attrs: nounwind uwtable
define void @cli_hex2int() {
entry:
br label %if.end
if.end: ; preds = %entry
%call = call i16** @__ctype_b_loc() #0
%tmp = load i16*, i16** %call, align 8
%arrayidx = getelementptr inbounds i16, i16* %tmp, i64 0
%tmp1 = load i16, i16* %arrayidx, align 2
br i1 false, label %if.then.2, label %if.end.3
if.then.2: ; preds = %if.end
br label %cleanup
if.end.3: ; preds = %if.end
br label %cleanup
cleanup: ; preds = %if.end.3, %if.then.2
ret void
}
; Function Attrs: nounwind readnone
declare i16** @__ctype_b_loc() #0
attributes #0 = { nounwind readnone }