[PATCH] Fix VGATHER* operand constraints
Add earlyclobber constaints to prevent input register being allocated as
the output register because, according to Intel spec [1], "If any pair
of the index, mask, or destination registers are the same, this
instruction results a UD fault."
---
[1] http://software.intel.com/sites/default/files/319433-014.pdf
llvm-svn: 183327
diff --git a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
index 02f5fe4..14ec2dd 100644
--- a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -2041,6 +2041,8 @@
case Intrinsic::x86_avx2_gather_d_d_256:
case Intrinsic::x86_avx2_gather_q_d:
case Intrinsic::x86_avx2_gather_q_d_256: {
+ if (!Subtarget->hasAVX2())
+ break;
unsigned Opc;
switch (IntNo) {
default: llvm_unreachable("Impossible intrinsic");