[llvm] r307508 - [X86] Relax an assertion when legalizing vector types.

[Davide Italiano via llvm-commits]

Author: davide
Date: Sun Jul  9 12:22:48 2017
New Revision: 307508

URL: http://llvm.org/viewvc/llvm-project?rev=307508&view=rev
Log:
[X86] Relax an assertion when legalizing vector types.

WidenVSELECTAndMask can fold (and it folds in this case) so we
get a BUILD_VECTOR of constants as mask. convertMask() seems to
work fine when the input is a vector of constants, and we still
need to call it to extend/add elements at the end. but the current
code just asserts on anything but a SETCC or AND/OR/XOR of 2xSETCC.
This change was discussed briefly with Simon Pilgrim, who also
suggests we might consider dropping this assertion in the future.

Fixes PR33715.

Added:
    llvm/trunk/test/CodeGen/X86/pr33715.ll
Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp?rev=307508&r1=307507&r2=307508&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp Sun Jul  9 12:22:48 2017
@@ -2977,7 +2977,11 @@ SDValue DAGTypeLegalizer::convertMask(SD
 
   // Currently a SETCC or a AND/OR/XOR with two SETCCs are handled.
   unsigned InMaskOpc = InMask->getOpcode();
+
+  // FIXME: This code seems to be too restrictive, we might consider
+  // generalizing it or dropping it.
   assert((InMaskOpc == ISD::SETCC ||
+          ISD::isBuildVectorOfConstantSDNodes(InMask.getNode()) ||
           (isLogicalMaskOp(InMaskOpc) &&
            isSETCCorConvertedSETCC(InMask->getOperand(0)) &&
            isSETCCorConvertedSETCC(InMask->getOperand(1)))) &&

Added: llvm/trunk/test/CodeGen/X86/pr33715.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/pr33715.ll?rev=307508&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/pr33715.ll (added)
+++ llvm/trunk/test/CodeGen/X86/pr33715.ll Sun Jul  9 12:22:48 2017
@@ -0,0 +1,16 @@
+; Make sure we don't crash with a build vector of integer constants.
+; RUN: llc %s -o /dev/null
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define i32 @patatino() {
+  %tmp = insertelement <4 x i32> <i32 1, i32 1, i32 undef, i32 undef>, i32 1, i32 2
+  %tmp1 = insertelement <4 x i32> %tmp, i32 1, i32 3
+  %tmp2 = icmp ne <4 x i32> %tmp1, zeroinitializer
+  %tmp3 = icmp slt <4 x i32> %tmp1, <i32 4, i32 4, i32 4, i32 4>
+  %tmp4 = or <4 x i1> %tmp2, %tmp3
+  %tmp5 = select <4 x i1> %tmp4, <4 x i32> zeroinitializer, <4 x i32> <i32 4, i32 4, i32 4, i32 4>
+  %tmp6 = extractelement <4 x i32> %tmp5, i32 0
+  ret i32 %tmp6
+}