NVPTX: support direct f16 <-> f64 conversions via intrinsics.

Clang may well start emitting these soon, and while it may not be
directly relevant for OpenCL or GLSL, the instructions were just
sitting there waiting to be used.

llvm-svn: 213356

diff --git a/llvm/lib/Target/NVPTX/NVPTXIntrinsics.td b/llvm/lib/Target/NVPTX/NVPTXIntrinsics.td
index 13f6532..14e51aa 100644 (file)
--- a/llvm/lib/Target/NVPTX/NVPTXIntrinsics.td
+++ b/llvm/lib/Target/NVPTX/NVPTXIntrinsics.td
@@ -799,6 +799,11 @@ def : Pat<(i16 (fp_to_f16 Float32Regs:$a)),
 def : Pat<(i16 (fp_to_f16 Float32Regs:$a)),
           (CVT_f16_f32 Float32Regs:$a, CvtRN)>;
 
+def : Pat<(f64 (f16_to_fp Int16Regs:$a)),
+          (CVT_f64_f16 Int16Regs:$a, CvtNONE)>;
+def : Pat<(i16 (fp_to_f16 Float64Regs:$a)),
+          (CVT_f16_f64 Float64Regs:$a, CvtRN)>;
+
 //
 // Bitcast
 //

diff --git a/llvm/test/CodeGen/NVPTX/fp16.ll b/llvm/test/CodeGen/NVPTX/fp16.ll
new file mode 100644 (file)
index 0000000..8770399
--- /dev/null
+++ b/llvm/test/CodeGen/NVPTX/fp16.ll
@@ -0,0 +1,45 @@
+; RUN: llc -march=nvptx -verify-machineinstrs < %s | FileCheck %s
+
+declare float @llvm.convert.from.fp16.f32(i16) nounwind readnone
+declare double @llvm.convert.from.fp16.f64(i16) nounwind readnone
+declare i16 @llvm.convert.to.fp16.f32(float) nounwind readnone
+declare i16 @llvm.convert.to.fp16.f64(double) nounwind readnone
+
+; CHECK-LABEL: @test_convert_fp16_to_fp32
+; CHECK: cvt.f32.f16
+define void @test_convert_fp16_to_fp32(float addrspace(1)* noalias %out, i16 addrspace(1)* noalias %in) nounwind {
+  %val = load i16 addrspace(1)* %in, align 2
+  %cvt = call float @llvm.convert.from.fp16.f32(i16 %val) nounwind readnone
+  store float %cvt, float addrspace(1)* %out, align 4
+  ret void
+}
+
+
+; CHECK-LABEL: @test_convert_fp16_to_fp64
+; CHECK: cvt.f64.f16
+define void @test_convert_fp16_to_fp64(double addrspace(1)* noalias %out, i16 addrspace(1)* noalias %in) nounwind {
+  %val = load i16 addrspace(1)* %in, align 2
+  %cvt = call double @llvm.convert.from.fp16.f64(i16 %val) nounwind readnone
+  store double %cvt, double addrspace(1)* %out, align 4
+  ret void
+}
+
+
+; CHECK-LABEL: @test_convert_fp32_to_fp16
+; CHECK: cvt.rn.f16.f32
+define void @test_convert_fp32_to_fp16(i16 addrspace(1)* noalias %out, float addrspace(1)* noalias %in) nounwind {
+  %val = load float addrspace(1)* %in, align 2
+  %cvt = call i16 @llvm.convert.to.fp16.f32(float %val) nounwind readnone
+  store i16 %cvt, i16 addrspace(1)* %out, align 4
+  ret void
+}
+
+
+; CHECK-LABEL: @test_convert_fp64_to_fp16
+; CHECK: cvt.rn.f16.f64
+define void @test_convert_fp64_to_fp16(i16 addrspace(1)* noalias %out, double addrspace(1)* noalias %in) nounwind {
+  %val = load double addrspace(1)* %in, align 2
+  %cvt = call i16 @llvm.convert.to.fp16.f64(double %val) nounwind readnone
+  store i16 %cvt, i16 addrspace(1)* %out, align 4
+  ret void
+}