[llvm] r214175 - ARM: fix @llvm.convert.from.fp16 on softfloat targets.

[Tim Northover]

Author: tnorthover
Date: Tue Jul 29 04:56:38 2014
New Revision: 214175

URL: http://llvm.org/viewvc/llvm-project?rev=214175&view=rev
Log:
ARM: fix @llvm.convert.from.fp16 on softfloat targets.

We need to make sure we use the softened version of all appropriate operands in
the libcall, or things go horribly wrong. This may entail actually executing a
1-stage softening.

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp
    llvm/trunk/test/CodeGen/ARM/fp16.ll

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp?rev=214175&r1=214174&r2=214175&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp Tue Jul 29 04:56:38 2014
@@ -377,10 +377,15 @@ SDValue DAGTypeLegalizer::SoftenFloatRes
   // There's only a libcall for f16 -> f32, so proceed in two stages. Also, it's
   // entirely possible for both f16 and f32 to be legal, so use the fully
   // hard-float FP_EXTEND rather than FP16_TO_FP.
-  if (Op.getValueType() == MVT::f16 && N->getValueType(0) != MVT::f32)
+  if (Op.getValueType() == MVT::f16 && N->getValueType(0) != MVT::f32) {
     Op = DAG.getNode(ISD::FP_EXTEND, SDLoc(N), MVT::f32, Op);
+    if (getTypeAction(MVT::f32) == TargetLowering::TypeSoftenFloat)
+      SoftenFloatResult(Op.getNode(), 0);
+  }
 
   RTLIB::Libcall LC = RTLIB::getFPEXT(Op.getValueType(), N->getValueType(0));
+  if (getTypeAction(Op.getValueType()) == TargetLowering::TypeSoftenFloat)
+    Op = GetSoftenedFloat(Op);
   assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unsupported FP_EXTEND!");
   return TLI.makeLibCall(DAG, LC, NVT, &Op, 1, false, SDLoc(N)).first;
 }

Modified: llvm/trunk/test/CodeGen/ARM/fp16.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/ARM/fp16.ll?rev=214175&r1=214174&r2=214175&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/ARM/fp16.ll (original)
+++ llvm/trunk/test/CodeGen/ARM/fp16.ll Tue Jul 29 04:56:38 2014
@@ -1,6 +1,8 @@
 ; RUN: llc < %s | FileCheck %s
 ; RUN: llc -mattr=+vfp3,+fp16 < %s | FileCheck --check-prefix=CHECK-FP16 %s
 ; RUN: llc -mtriple=armv8-eabi < %s | FileCheck --check-prefix=CHECK-ARMV8 %s
+; RUN: llc -mtriple=thumbv7m-eabi < %s | FileCheck --check-prefix=CHECK-SOFTFLOAT %s
+
 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-n32"
 target triple = "armv7-eabi"
 
@@ -12,6 +14,7 @@ define arm_aapcs_vfpcc void @foo() nounw
 ; CHECK-LABEL: foo:
 ; CHECK-FP16-LABEL: foo:
 ; CHECK-ARMV8-LABEL: foo:
+; CHECK-SOFTFLOAT-LABEL: foo:
 entry:
   %0 = load i16* @x, align 2
   %1 = load i16* @y, align 2
@@ -19,15 +22,18 @@ entry:
 ; CHECK: __gnu_h2f_ieee
 ; CHECK-FP16: vcvtb.f32.f16
 ; CHECK-ARMv8: vcvtb.f32.f16
+; CHECK-SOFTFLOAT: __gnu_h2f_ieee
   %3 = tail call float @llvm.convert.from.fp16.f32(i16 %1)
 ; CHECK: __gnu_h2f_ieee
 ; CHECK-FP16: vcvtb.f32.f16
 ; CHECK-ARMV8: vcvtb.f32.f16
+; CHECK-SOFTFLOAT: __gnu_h2f_ieee
   %4 = fadd float %2, %3
   %5 = tail call i16 @llvm.convert.to.fp16.f32(float %4)
 ; CHECK: __gnu_f2h_ieee
 ; CHECK-FP16: vcvtb.f16.f32
 ; CHECK-ARMV8: vcvtb.f16.f32
+; CHECK-SOFTFLOAT: __gnu_f2h_ieee
   store i16 %5, i16* @x, align 2
   ret void
 }
@@ -36,6 +42,7 @@ define arm_aapcs_vfpcc double @test_from
 ; CHECK-LABEL: test_from_fp16:
 ; CHECK-FP-LABEL: test_from_fp16:
 ; CHECK-ARMV8-LABEL: test_from_fp16:
+; CHECK-SOFTFLOAT-LABEL: test_from_fp16:
   %val = call double @llvm.convert.from.fp16.f64(i16 %in)
 ; CHECK: bl __gnu_h2f_ieee
 ; CHECK: vmov [[TMP:s[0-9]+]], r0
@@ -47,6 +54,9 @@ define arm_aapcs_vfpcc double @test_from
 
 ; CHECK-ARMV8: vmov [[TMP:s[0-9]+]], r0
 ; CHECK-ARMV8: vcvtb.f64.f16 d0, [[TMP]]
+
+; CHECK-SOFTFLOAT: bl __gnu_h2f_ieee
+; CHECK-SOFTFLOAT: bl __aeabi_f2d
   ret double %val
 }
 
@@ -54,6 +64,7 @@ define arm_aapcs_vfpcc i16 @test_to_fp16
 ; CHECK-LABEL: test_to_fp16:
 ; CHECK-FP-LABEL: test_to_fp16:
 ; CHECK-ARMV8-LABEL: test_to_fp16:
+; CHECK-SOFTFLOAT-LABEL: test_to_fp16:
   %val = call i16 @llvm.convert.to.fp16.f64(double %in)
 ; CHECK: bl __truncdfhf2
 
@@ -61,6 +72,8 @@ define arm_aapcs_vfpcc i16 @test_to_fp16
 
 ; CHECK-ARMV8: vcvtb.f16.f64 [[TMP:s[0-9]+]], d0
 ; CHECK-ARMV8: vmov r0, [[TMP]]
+
+; CHECK-SOFTFLOAT: bl __truncdfhf2
   ret i16 %val
 }