From 39d772ac647c6a5a596a0de802f5a3aa025130e1 Mon Sep 17 00:00:00 2001
From: Ahmed Bougacha <ahmed.bougacha@gmail.com>
Date: Thu, 13 Aug 2015 01:09:43 +0000
Subject: [PATCH] [CodeGen] When Promoting, don't extend the 2nd FCOPYSIGN
 operand.

We don't care about its type, and there's even a combine that'll fold
away the FP_EXTEND if we let it run. However, until it does, we'll have
something broken like:
  (f32 (fp_extend (f64 v)))

Scalar f16 follow-up to r243924.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244858 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/SelectionDAG/LegalizeDAG.cpp |  2 +-
 test/CodeGen/AArch64/f16-instructions.ll | 37 ++++++++++++++++++++++--
 2 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 8360b3d064a..3b15752e2e4 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -4278,7 +4278,6 @@ void SelectionDAGLegalize::PromoteNode(SDNode *Node) {
   case ISD::FREM:
   case ISD::FMINNUM:
   case ISD::FMAXNUM:
-  case ISD::FCOPYSIGN:
   case ISD::FPOW: {
     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
@@ -4297,6 +4296,7 @@ void SelectionDAGLegalize::PromoteNode(SDNode *Node) {
                     DAG.getIntPtrConstant(0, dl)));
     break;
   }
+  case ISD::FCOPYSIGN:
   case ISD::FPOWI: {
     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
     Tmp2 = Node->getOperand(1);
diff --git a/test/CodeGen/AArch64/f16-instructions.ll b/test/CodeGen/AArch64/f16-instructions.ll
index 0cadfc8c44b..26fc3a9ae24 100644
--- a/test/CodeGen/AArch64/f16-instructions.ll
+++ b/test/CodeGen/AArch64/f16-instructions.ll
@@ -666,17 +666,48 @@ define half @test_maxnum(half %a, half %b) #0 {
 }
 
 ; CHECK-LABEL: test_copysign:
-; CHECK-NEXT: fcvt s1, h1
+; CHECK-NEXT: sub sp, sp, #16
+; CHECK-NEXT: str h1, [sp, #8]
+; CHECK-NEXT: ldr x8, [sp, #8]
 ; CHECK-NEXT: fcvt s0, h0
-; CHECK-NEXT: movi.4s v2, #0x80, lsl #24
-; CHECK-NEXT: bit.16b v0, v1, v2
+; CHECK-NEXT: fabs s0, s0
+; CHECK-NEXT: fneg s1, s0
+; CHECK-NEXT: lsl x8, x8, #48
+; CHECK-NEXT: cmp  x8, #0
+; CHECK-NEXT: fcsel s0, s1, s0, lt
 ; CHECK-NEXT: fcvt h0, s0
+; CHECK-NEXT: add sp, sp, #16
 ; CHECK-NEXT: ret
 define half @test_copysign(half %a, half %b) #0 {
   %r = call half @llvm.copysign.f16(half %a, half %b)
   ret half %r
 }
 
+; CHECK-LABEL: test_copysign_f32:
+; CHECK-NEXT: fcvt s0, h0
+; CHECK-NEXT: movi.4s v2, #0x80, lsl #24
+; CHECK-NEXT: bit.16b v0, v1, v2
+; CHECK-NEXT: fcvt h0, s0
+; CHECK-NEXT: ret
+define half @test_copysign_f32(half %a, float %b) #0 {
+  %tb = fptrunc float %b to half
+  %r = call half @llvm.copysign.f16(half %a, half %tb)
+  ret half %r
+}
+
+; CHECK-LABEL: test_copysign_f64:
+; CHECK-NEXT: fcvt s1, d1
+; CHECK-NEXT: fcvt s0, h0
+; CHECK-NEXT: movi.4s v2, #0x80, lsl #24
+; CHECK-NEXT: bit.16b v0, v1, v2
+; CHECK-NEXT: fcvt h0, s0
+; CHECK-NEXT: ret
+define half @test_copysign_f64(half %a, double %b) #0 {
+  %tb = fptrunc double %b to half
+  %r = call half @llvm.copysign.f16(half %a, half %tb)
+  ret half %r
+}
+
 ; CHECK-LABEL: test_floor:
 ; CHECK-NEXT: fcvt [[FLOAT32:s[0-9]+]], h0
 ; CHECK-NEXT: frintm [[INT32:s[0-9]+]], [[FLOAT32]]
-- 
2.34.1