Fix slightly too aggressive conact_vector optimization.

(Would sometimes optimize away conacts used to extend a vector with undef values)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181186 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Michael Kuperstein 2013-05-06 08:06:13 +00:00
parent 10c6d2c84c
commit 2720248ae5
2 changed files with 20 additions and 0 deletions

View File

@ -9145,6 +9145,12 @@ SDValue DAGCombiner::visitCONCAT_VECTORS(SDNode *N) {
return SDValue(); return SDValue();
} else { } else {
SingleSource = Op.getOperand(0); SingleSource = Op.getOperand(0);
// Check the source type is the same as the type of the result.
// If not, this concat may extend the vector, so we can not
// optimize it away.
if (SingleSource.getValueType() != N->getValueType(0))
return SDValue();
} }
unsigned IdentityIndex = i * PartNumElem; unsigned IdentityIndex = i * PartNumElem;

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@ -0,0 +1,14 @@
; RUN: llc < %s -march=x86
; Make sure this doesn't crash
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
target triple = "x86_64-pc-win32"
define void @foo() {
%1 = shufflevector <3 x i8> undef, <3 x i8> undef, <2 x i32> <i32 0, i32 1>
%2 = shufflevector <2 x i8> %1, <2 x i8> undef, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
%3 = shufflevector <4 x i8> undef, <4 x i8> %2, <4 x i32> <i32 0, i32 1, i32 4, i32 5>
store <4 x i8> %3, <4 x i8>* undef
ret void
}