In SimplifySelectOps we pulled two loads through a select node despite the fact that one was dependent on the other.

rdar://12513091

llvm-svn: 166196
This commit is contained in:
Nadav Rotem 2012-10-18 18:06:48 +00:00
parent 4d3611ca82
commit d5f8859672
2 changed files with 65 additions and 0 deletions

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@ -9075,6 +9075,10 @@ bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDValue LHS,
if ((LLD->hasAnyUseOfValue(1) && LLD->isPredecessorOf(CondNode)) ||
(RLD->hasAnyUseOfValue(1) && RLD->isPredecessorOf(CondNode)))
return false;
// The loads must not depend on one another.
if (LLD->isPredecessorOf(RLD) ||
RLD->isPredecessorOf(LLD))
return false;
Addr = DAG.getNode(ISD::SELECT, TheSelect->getDebugLoc(),
LLD->getBasePtr().getValueType(),
TheSelect->getOperand(0), LLD->getBasePtr(),

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@ -0,0 +1,61 @@
; RUN: llc -march=x86-64 -mcpu=corei7 -disable-cgp-select2branch < %s
; We should not crash on this test.
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-n8:16:32"
target triple = "i386-apple-darwin9.0.0"
@global = external constant [411 x i8], align 1
define void @snork() nounwind {
bb:
br i1 undef, label %bb26, label %bb27
bb26: ; preds = %bb48, %bb26, %bb
switch i32 undef, label %bb26 [
i32 142771596, label %bb28
]
bb27: ; preds = %bb48, %bb
switch i32 undef, label %bb49 [
i32 142771596, label %bb28
]
bb28: ; preds = %bb27, %bb26
%tmp = load i32* null
%tmp29 = trunc i32 %tmp to i8
store i8* undef, i8** undef
%tmp30 = load i32* null
%tmp31 = icmp eq i32 %tmp30, 0
%tmp32 = getelementptr inbounds [411 x i8]* @global, i32 0, i32 undef
%tmp33 = load i8* %tmp32, align 1
%tmp34 = getelementptr inbounds [411 x i8]* @global, i32 0, i32 0
%tmp35 = load i8* %tmp34, align 1
%tmp36 = select i1 %tmp31, i8 %tmp35, i8 %tmp33
%tmp37 = select i1 undef, i8 %tmp29, i8 %tmp36
%tmp38 = zext i8 %tmp37 to i32
%tmp39 = select i1 undef, i32 0, i32 %tmp38
%tmp40 = getelementptr inbounds i32* null, i32 %tmp39
%tmp41 = load i32* %tmp40, align 4
%tmp42 = load i32* undef, align 4
%tmp43 = load i32* undef
%tmp44 = xor i32 %tmp42, %tmp43
%tmp45 = lshr i32 %tmp44, 8
%tmp46 = lshr i32 %tmp44, 7
call void @spam()
unreachable
bb47: ; No predecessors!
ret void
bb48: ; No predecessors!
br i1 undef, label %bb27, label %bb26
bb49: ; preds = %bb49, %bb27
br label %bb49
bb50: ; preds = %bb50
br label %bb50
}
declare void @spam() noreturn nounwind