AMDGPU: Fix assert on trunc from bitcast of build_vector

The v2i64 argument is lowered to a bitcast of v4i32 build_vector.
This would then attempt to use the i32-element as the source of the
vector truncate. This really would need to collect 2 elements from the
build_vector to produce the intended truncate.

llvm-svn: 353202

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
index a15b2b99220..0f0d877685d 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
@@ -3088,7 +3088,7 @@ SDValue AMDGPUTargetLowering::performTruncateCombine(
   SDValue Src = N->getOperand(0);
 
   // vt1 (truncate (bitcast (build_vector vt0:x, ...))) -> vt1 (bitcast vt0:x)
-  if (Src.getOpcode() == ISD::BITCAST) {
+  if (Src.getOpcode() == ISD::BITCAST && !VT.isVector()) {
     SDValue Vec = Src.getOperand(0);
     if (Vec.getOpcode() == ISD::BUILD_VECTOR) {
       SDValue Elt0 = Vec.getOperand(0);