From e683321270509ae88ddf143f2b33cafcc489b44c Mon Sep 17 00:00:00 2001
From: Tim Northover <tnorthover@apple.com>
Date: Fri, 18 Jul 2014 13:01:25 +0000
Subject: [PATCH] X86: support fpext/fptrunc operations to and from 16-bit
 floats.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213374 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86ISelLowering.cpp |  5 ++++
 test/CodeGen/X86/half.ll           | 42 ++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index ae123569a89..d5d11fea341 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -529,6 +529,11 @@ void X86TargetLowering::resetOperationActions() {
   setOperationAction(ISD::FP_TO_FP16, MVT::f64, Expand);
   setOperationAction(ISD::FP_TO_FP16, MVT::f80, Expand);
 
+  setLoadExtAction(ISD::EXTLOAD, MVT::f16, Expand);
+  setTruncStoreAction(MVT::f32, MVT::f16, Expand);
+  setTruncStoreAction(MVT::f64, MVT::f16, Expand);
+  setTruncStoreAction(MVT::f80, MVT::f16, Expand);
+
   if (Subtarget->hasPOPCNT()) {
     setOperationAction(ISD::CTPOP          , MVT::i8   , Promote);
   } else {
diff --git a/test/CodeGen/X86/half.ll b/test/CodeGen/X86/half.ll
index 150edaf99bd..1dcf93939b8 100644
--- a/test/CodeGen/X86/half.ll
+++ b/test/CodeGen/X86/half.ll
@@ -25,3 +25,45 @@ define void @test_bitcast_to_half(half* %addr, i16 %in) {
   store half %val_fp, half* %addr
   ret void
 }
+
+define float @test_extend32(half* %addr) {
+; CHECK-LABEL: test_extend32:
+
+; CHECK-LIBCALL: jmp __gnu_h2f_ieee
+; CHECK-FP16: vcvtph2ps
+  %val16 = load half* %addr
+  %val32 = fpext half %val16 to float
+  ret float %val32
+}
+
+define double @test_extend64(half* %addr) {
+; CHECK-LABEL: test_extend64:
+
+; CHECK-LIBCALL: callq __gnu_h2f_ieee
+; CHECK-LIBCALL: cvtss2sd
+; CHECK-FP16: vcvtph2ps
+; CHECK-FP16: vcvtss2sd
+  %val16 = load half* %addr
+  %val32 = fpext half %val16 to double
+  ret double %val32
+}
+
+define void @test_trunc32(float %in, half* %addr) {
+; CHECK-LABEL: test_trunc32:
+
+; CHECK-LIBCALL: callq __gnu_f2h_ieee
+; CHECK-FP16: vcvtps2ph
+  %val16 = fptrunc float %in to half
+  store half %val16, half* %addr
+  ret void
+}
+
+define void @test_trunc64(double %in, half* %addr) {
+; CHECK-LABEL: test_trunc64:
+
+; CHECK-LIBCALL: callq __truncdfhf2
+; CHECK-FP16: callq __truncdfhf2
+  %val16 = fptrunc double %in to half
+  store half %val16, half* %addr
+  ret void
+}