RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-10-19 19:12:56 +02:00
Code Issues Projects Releases Wiki Activity

[GVNHoist] Don't hoist PHI nodes

Browse Source 
We hoisted PHIs without respecting their special insertion point in the
block, leading to verfier errors.

This fixes PR28626.

llvm-svn: 276181
This commit is contained in:
David Majnemer 2016-07-20 21:05:01 +00:00
parent 136d0901cf
commit cb8a4f8570
2 changed files with 50 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
lib/Transforms/Scalar/GVNHoist.cpp
View File

@ -576,16 +576,20 @@ public:
bool makeOperandsAvailable(Instruction *Repl, BasicBlock *HoistPt) const {
// Check whether the GEP of a ld/st can be synthesized at HoistPt.
Instruction *Gep = nullptr;
GetElementPtrInst *Gep = nullptr;
Instruction *Val = nullptr;
if (auto *Ld = dyn_cast<LoadInst>(Repl))
Gep = dyn_cast<Instruction>(Ld->getPointerOperand());
Gep = dyn_cast<GetElementPtrInst>(Ld->getPointerOperand());
if (auto *St = dyn_cast<StoreInst>(Repl)) {
Gep = dyn_cast<Instruction>(St->getPointerOperand());
Gep = dyn_cast<GetElementPtrInst>(St->getPointerOperand());
Val = dyn_cast<Instruction>(St->getValueOperand());
}
if (!Gep || !isa<GetElementPtrInst>(Gep))
if (!Gep)
return false;
// PHIs may only be inserted at the start of a block.
if (Val && isa<PHINode>(Val))
return false;
// Check whether we can compute the Gep at HoistPt.

42
test/Transforms/GVN/pr28626.ll Normal file
View File

@ -0,0 +1,42 @@
; RUN: opt -S -gvn-hoist < %s | FileCheck %s
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
define void @test1(i1 %a, i1** %d) {
entry:
%0 = load i1*, i1** %d, align 8
br i1 %a, label %if.then, label %if.else
if.then: ; preds = %entry
br label %if.end
if.else: ; preds = %entry
br label %if.end
if.end: ; preds = %if.else, %if.then
%c.0 = phi i1 [ 1, %if.then ], [ 0, %if.else ]
br i1 %c.0, label %if.then2, label %if.else3
if.then2: ; preds = %if.end
%rc = getelementptr inbounds i1, i1* %0, i64 0
store i1 %c.0, i1* %rc, align 4
br label %if.end6
if.else3: ; preds = %if.end
%rc5 = getelementptr inbounds i1, i1* %0, i64 0
store i1 %c.0, i1* %rc5, align 4
br label %if.end6
if.end6: ; preds = %if.else3, %if.then2
ret void
}
; CHECK-LABEL: define void @test1(
; CHECK: %[[load:.*]] = load i1*, i1** %d, align 8
; CHECK: %[[phi:.*]] = phi i1 [ true, {{.*}} ], [ false, {{.*}} ]
; CHECK: %[[gep0:.*]] = getelementptr inbounds i1, i1* %[[load]], i64 0
; CHECK: store i1 %[[phi]], i1* %[[gep0]], align 4
; CHECK: %[[gep1:.*]] = getelementptr inbounds i1, i1* %[[load]], i64 0
; CHECK: store i1 %[[phi]], i1* %[[gep1]], align 4