From: Hans Wennborg <hans@hanshq.net>
Date: Thu, 16 Aug 2018 09:58:56 +0000 (+0000)
Subject: Merging r339533:
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=0caaac00354f81b19bdd453719e9ae2a2ae8e791;p=llvm
Merging r339533:
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r339533 | ctopper | 2018-08-13 07:26:49 +0200 (Mon, 13 Aug 2018) | 5 lines
[SelectionDAG] In PromoteFloatRes_BITCAST, insert a bitcast before the fp16_to_fp in case the input type isn't an i16.
The bitcast can be further legalized as needed.
Fixes PR38533.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_70@339855 91177308-0d34-0410-b5e6-96231b3b80d8
---
diff --git a/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp b/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp
index 9aa0ea15f3b..feca1c10f52 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp
@@ -1941,8 +1941,10 @@ void DAGTypeLegalizer::PromoteFloatResult(SDNode *N, unsigned ResNo) {
SDValue DAGTypeLegalizer::PromoteFloatRes_BITCAST(SDNode *N) {
EVT VT = N->getValueType(0);
EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), VT);
- return DAG.getNode(GetPromotionOpcode(VT, NVT), SDLoc(N), NVT,
- N->getOperand(0));
+ // Input type isn't guaranteed to be i16 so bitcast if not. The bitcast
+ // will be legalized further if necessary.
+ SDValue Cast = DAG.getBitcast(MVT::i16, N->getOperand(0));
+ return DAG.getNode(GetPromotionOpcode(VT, NVT), SDLoc(N), NVT, Cast);
}
SDValue DAGTypeLegalizer::PromoteFloatRes_ConstantFP(SDNode *N) {
diff --git a/test/CodeGen/X86/pr38533.ll b/test/CodeGen/X86/pr38533.ll
new file mode 100644
index 00000000000..4c57d84fe65
--- /dev/null
+++ b/test/CodeGen/X86/pr38533.ll
@@ -0,0 +1,11 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=x86_64-unknown | FileCheck %s
+
+define void @constant_fold_vector_to_half() {
+; CHECK-LABEL: constant_fold_vector_to_half:
+; CHECK: # %bb.0:
+; CHECK-NEXT: movw $16384, (%rax) # imm = 0x4000
+; CHECK-NEXT: retq
+ store volatile half bitcast (<4 x i4> <i4 0, i4 0, i4 0, i4 4> to half), half* undef
+ ret void
+}