From 959f0c3f44db98d6861e399c58bfc2066bee739e Mon Sep 17 00:00:00 2001 From: Daniel Sanders Date: Thu, 21 Nov 2013 16:11:31 +0000 Subject: [PATCH] [mips][msa] Fix a corner case in performORCombine() when combining nodes into VSELECT. Mask == ~InvMask asserts if the width of Mask and InvMask differ. The combine isn't valid (with two exceptions, see below) if the widths differ so test for this before testing Mask == ~InvMask. In the specific cases of Mask=~0 and InvMask=0, as well as Mask=0 and InvMask=~0, the combine is still valid. However, there are more appropriate combines that could be used in these cases such as folding x & 0 to 0, or x & ~0 to x. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195364 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/Mips/MipsSEISelLowering.cpp | 12 ++++--- .../msa/llvm-stress-s449609655-simplified.ll | 33 +++++++++++++++++++ 2 files changed, 41 insertions(+), 4 deletions(-) create mode 100644 test/CodeGen/Mips/msa/llvm-stress-s449609655-simplified.ll diff --git a/lib/Target/Mips/MipsSEISelLowering.cpp b/lib/Target/Mips/MipsSEISelLowering.cpp index 274cdc1f89a..27d7515c40c 100644 --- a/lib/Target/Mips/MipsSEISelLowering.cpp +++ b/lib/Target/Mips/MipsSEISelLowering.cpp @@ -594,9 +594,11 @@ static SDValue performORCombine(SDNode *N, SelectionDAG &DAG, Cond = Op0Op0; IfSet = Op0Op1; - if (isVSplat(Op1Op0, InvMask, IsLittleEndian) && Mask == ~InvMask) + if (isVSplat(Op1Op0, InvMask, IsLittleEndian) && + Mask.getBitWidth() == InvMask.getBitWidth() && Mask == ~InvMask) IfClr = Op1Op1; - else if (isVSplat(Op1Op1, InvMask, IsLittleEndian) && Mask == ~InvMask) + else if (isVSplat(Op1Op1, InvMask, IsLittleEndian) && + Mask.getBitWidth() == InvMask.getBitWidth() && Mask == ~InvMask) IfClr = Op1Op0; IsConstantMask = true; @@ -609,9 +611,11 @@ static SDValue performORCombine(SDNode *N, SelectionDAG &DAG, Cond = Op0Op1; IfSet = Op0Op0; - if (isVSplat(Op1Op0, InvMask, IsLittleEndian) && Mask == ~InvMask) + if (isVSplat(Op1Op0, InvMask, IsLittleEndian) && + Mask.getBitWidth() == InvMask.getBitWidth() && Mask == ~InvMask) IfClr = Op1Op1; - else if (isVSplat(Op1Op1, InvMask, IsLittleEndian) && Mask == ~InvMask) + else if (isVSplat(Op1Op1, InvMask, IsLittleEndian) && + Mask.getBitWidth() == InvMask.getBitWidth() && Mask == ~InvMask) IfClr = Op1Op0; IsConstantMask = true; diff --git a/test/CodeGen/Mips/msa/llvm-stress-s449609655-simplified.ll b/test/CodeGen/Mips/msa/llvm-stress-s449609655-simplified.ll new file mode 100644 index 00000000000..24e27cbf14b --- /dev/null +++ b/test/CodeGen/Mips/msa/llvm-stress-s449609655-simplified.ll @@ -0,0 +1,33 @@ +; RUN: llc -march=mips < %s +; RUN: llc -march=mips -mattr=+msa,+fp64 < %s +; RUN: llc -march=mipsel < %s +; RUN: llc -march=mipsel -mattr=+msa,+fp64 < %s + +; This test is based on an llvm-stress generated test case with seed=449609655 + +; This test originally failed for MSA with a +; "Comparison requires equal bit widths" assertion. +; The legalizer legalized ; the <4 x i8>'s into <4 x i32>'s, then a call to +; isVSplat() returned the splat value for as a 32-bit APInt +; (255), but the zeroinitializer splat value as an 8-bit APInt (0). The +; assertion occured when trying to check the values were bitwise inverses of +; each-other. +; +; It should at least successfully build. + +define void @autogen_SD449609655(i8) { +BB: + %Cmp = icmp ult i8 -3, %0 + br label %CF78 + +CF78: ; preds = %CF81, %CF78, %BB + %Sl31 = select i1 %Cmp, <4 x i8> , <4 x i8> zeroinitializer + br i1 undef, label %CF78, label %CF81 + +CF81: ; preds = %CF78 + br i1 undef, label %CF78, label %CF80 + +CF80: ; preds = %CF81 + %I59 = insertelement <4 x i8> %Sl31, i8 undef, i32 1 + ret void +}