Merging r195476:
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r195476 | hliao | 2013-11-22 09:56:57 -0800 (Fri, 22 Nov 2013) | 6 lines
Fix PR18014
- When simplifying the mask generation for BLEND, check whether that mask is
also consumed by other non-BLEND insns. If true, skip that simplification.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_34@195602 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 9df0232..627aa86 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -17007,6 +17007,15 @@
if (BitWidth == 1)
return SDValue();
+ // Check all uses of that condition operand to check whether it will be
+ // consumed by non-BLEND instructions, which may depend on all bits are set
+ // properly.
+ for (SDNode::use_iterator I = Cond->use_begin(),
+ E = Cond->use_end(); I != E; ++I)
+ if (I->getOpcode() != ISD::VSELECT)
+ // TODO: Add other opcodes eventually lowered into BLEND.
+ return SDValue();
+
assert(BitWidth >= 8 && BitWidth <= 64 && "Invalid mask size");
APInt DemandedMask = APInt::getHighBitsSet(BitWidth, 1);