Add flag to enable native half type

Summary:
r235215 enables support in LLVM for legalizing f16 type in the IR.  AArch64
already had support for this.  r235215 and some backend patches brought support
for ARM, X86, X86-64, Mips and Mips64.

This change exposes the LangOption 'NativeHalfType' in the command line, so the
backend legalization can be used if desired.  NativeHalfType is enabled for
OpenCL (current behavior) or if '-fnative-half-type' is set.

Reviewers: olista01, steven_wu, ab

Subscribers: cfe-commits, srhines, aemerson

Differential Revision: http://reviews.llvm.org/D9781

llvm-svn: 237406

3 files changed, 142 insertions, 37 deletions

diff --git a/clang/include/clang/Driver/CC1Options.td b/clang/include/clang/Driver/CC1Options.td
index a861428ccef..9c1b561bca3 100644
--- a/clang/include/clang/Driver/CC1Options.td
+++ b/clang/include/clang/Driver/CC1Options.td
@@ -547,6 +547,8 @@ def vtordisp_mode_EQ : Joined<["-"], "vtordisp-mode=">,
   HelpText<"Control vtordisp placement on win32 targets">;
 def fno_rtti_data : Flag<["-"], "fno-rtti-data">,
   HelpText<"Control emission of RTTI data">;
+def fnative_half_type: Flag<["-"], "fnative-half-type">,
+  HelpText<"Use the native half type for __fp16 instead of promoting to float">;
 def fallow_half_arguments_and_returns : Flag<["-"], "fallow-half-arguments-and-returns">,
   HelpText<"Allow function arguments and returns of type half">;
 
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index d2514acd6de..1d6723f33a0 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1587,7 +1587,7 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
   Opts.ImplementationOfModule =
       Args.getLastArgValue(OPT_fmodule_implementation_of);
   Opts.ModuleFeatures = Args.getAllArgValues(OPT_fmodule_feature);
-  Opts.NativeHalfType = Opts.NativeHalfType;
+  Opts.NativeHalfType |= Args.hasArg(OPT_fnative_half_type);
   Opts.HalfArgsAndReturns = Args.hasArg(OPT_fallow_half_arguments_and_returns);
   Opts.GNUAsm = !Args.hasArg(OPT_fno_gnu_inline_asm);
 
diff --git a/clang/test/CodeGen/fp16-ops.c b/clang/test/CodeGen/fp16-ops.c
index 0c218be0ec5..fe0fa2c2667 100644
--- a/clang/test/CodeGen/fp16-ops.c
+++ b/clang/test/CodeGen/fp16-ops.c
@@ -3,6 +3,10 @@
 // RUN: %clang_cc1 -emit-llvm -o - -triple aarch64-none-linux-gnueabi %s | FileCheck %s --check-prefix=NOHALF --check-prefix=CHECK
 // RUN: %clang_cc1 -emit-llvm -o - -triple arm-none-linux-gnueabi -fallow-half-arguments-and-returns %s | FileCheck %s --check-prefix=HALF --check-prefix=CHECK
 // RUN: %clang_cc1 -emit-llvm -o - -triple aarch64-none-linux-gnueabi -fallow-half-arguments-and-returns %s | FileCheck %s --check-prefix=HALF --check-prefix=CHECK
+// RUN: %clang_cc1 -emit-llvm -o - -triple arm-none-linux-gnueabi -fnative-half-type %s \
+// RUN:   | FileCheck %s --check-prefix=NATIVE-HALF
+// RUN: %clang_cc1 -emit-llvm -o - -triple aarch64-none-linux-gnueabi -fnative-half-type %s \
+// RUN:   | FileCheck %s --check-prefix=NATIVE-HALF
 typedef unsigned cond_t;
 
 volatile cond_t test;
@@ -18,37 +22,47 @@ void foo(void) {
   // NOHALF: [[F16TOF32:call float @llvm.convert.from.fp16.f32]]
   // HALF: [[F16TOF32:fpext half]]
   // CHECK: fptoui float
+  // NATIVE-HALF: fptoui half
   test = (h0);
   // CHECK: uitofp i32
   // NOHALF: [[F32TOF16:call i16 @llvm.convert.to.fp16.f32]]
   // HALF: [[F32TOF16:fptrunc float]]
+  // NATIVE-HALF: uitofp i32 {{.*}} to half
   h0 = (test);
   // CHECK: [[F16TOF32]]
   // CHECK: fcmp une float
+  // NATIVE-HALF: fcmp une half
   test = (!h1);
   // CHECK: [[F16TOF32]]
   // CHECK: fsub float
   // NOHALF: [[F32TOF16]]
   // HALF: [[F32TOF16]]
+  // NATIVE-HALF: fsub half
   h1 = -h1;
   // CHECK: [[F16TOF32]]
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: load volatile half
+  // NATIVE-HALF-NEXT: store volatile half
   h1 = +h1;
   // CHECK: [[F16TOF32]]
   // CHECK: fadd float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fadd half
   h1++;
   // CHECK: [[F16TOF32]]
   // CHECK: fadd float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fadd half
   ++h1;
   // CHECK: [[F16TOF32]]
   // CHECK: fadd float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fadd half
   --h1;
   // CHECK: [[F16TOF32]]
   // CHECK: fadd float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fadd half
   h1--;
 
   // Check binary ops with various operands
@@ -56,259 +70,348 @@ void foo(void) {
   // CHECK: [[F16TOF32]]
   // CHECK: fmul float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fmul half
   h1 = h0 * h2;
   // CHECK: [[F16TOF32]]
   // NOHALF: [[F32TOF16]]
   // NOHALF: [[F16TOF32]]
   // CHECK: fmul float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fmul half
   h1 = h0 * (__fp16) -2.0f;
   // CHECK: [[F16TOF32]]
   // CHECK: fmul float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fmul float
   h1 = h0 * f2;
   // CHECK: [[F16TOF32]]
   // CHECK: fmul float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fmul float
   h1 = f0 * h2;
 
   // CHECK: [[F16TOF32]]
   // CHECK: [[F16TOF32]]
   // CHECK: fdiv float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fdiv half
   h1 = (h0 / h2);
   // CHECK: [[F16TOF32]]
   // NOHALF: [[F16TOF32]]
   // CHECK: fdiv float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fdiv half
   h1 = (h0 / (__fp16) -2.0f);
   // CHECK: [[F16TOF32]]
   // CHECK: fdiv float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fdiv float
   h1 = (h0 / f2);
   // CHECK: [[F16TOF32]]
   // CHECK: fdiv float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fdiv float
   h1 = (f0 / h2);
 
   // CHECK: [[F16TOF32]]
   // CHECK: [[F16TOF32]]
   // CHECK: fadd float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fadd half
   h1 = (h2 + h0);
   // CHECK: [[F16TOF32]]
   // NOHALF: [[F16TOF32]]
   // CHECK: fadd float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fadd half
   h1 = ((__fp16)-2.0 + h0);
   // CHECK: [[F16TOF32]]
   // CHECK: fadd float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fadd float
   h1 = (h2 + f0);
   // CHECK: [[F16TOF32]]
   // CHECK: fadd float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fadd float
   h1 = (f2 + h0);
 
   // CHECK: [[F16TOF32]]
   // CHECK: [[F16TOF32]]
   // CHECK: fsub float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fsub half
   h1 = (h2 - h0);
   // CHECK: [[F16TOF32]]
   // NOHALF: [[F16TOF32]]
   // CHECK: fsub float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fsub half
   h1 = ((__fp16)-2.0f - h0);
   // CHECK: [[F16TOF32]]
   // CHECK: fsub float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fsub float
   h1 = (h2 - f0);
   // CHECK: [[F16TOF32]]
   // CHECK: fsub float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fsub float
   h1 = (f2 - h0);
 
   // CHECK: [[F16TOF32]]
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp olt
+  // CHECK: fcmp olt float
+  // NATIVE-HALF: fcmp olt half
   test = (h2 < h0);
   // CHECK: [[F16TOF32]]
   // NOHALF: [[F16TOF32]]
-  // CHECK: fcmp olt
+  // CHECK: fcmp olt float
+  // NATIVE-HALF: fcmp olt half
   test = (h2 < (__fp16)42.0);
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp olt
+  // CHECK: fcmp olt float
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fcmp olt float
   test = (h2 < f0);
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp olt
+  // CHECK: fcmp olt float
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fcmp olt float
   test = (f2 < h0);
 
   // CHECK: [[F16TOF32]]
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp ogt
+  // CHECK: fcmp ogt float
+  // NATIVE-HALF: fcmp ogt half
   test = (h0 > h2);
   // CHECK: [[F16TOF32]]
   // NOHALF: [[F16TOF32]]
-  // CHECK: fcmp ogt
+  // CHECK: fcmp ogt float
+  // NATIVE-HALF: fcmp ogt half
   test = ((__fp16)42.0 > h2);
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp ogt
+  // CHECK: fcmp ogt float
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fcmp ogt float
   test = (h0 > f2);
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp ogt
+  // CHECK: fcmp ogt float
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fcmp ogt float
   test = (f0 > h2);
 
   // CHECK: [[F16TOF32]]
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp ole
+  // CHECK: fcmp ole float
+  // NATIVE-HALF: fcmp ole half
   test = (h2 <= h0);
   // CHECK: [[F16TOF32]]
   // NOHALF: [[F16TOF32]]
-  // CHECK: fcmp ole
+  // CHECK: fcmp ole float
+  // NATIVE-HALF: fcmp ole half
   test = (h2 <= (__fp16)42.0);
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp ole
+  // CHECK: fcmp ole float
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fcmp ole float
   test = (h2 <= f0);
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp ole
+  // CHECK: fcmp ole float
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fcmp ole float
   test = (f2 <= h0);
 
   // CHECK: [[F16TOF32]]
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp oge
+  // CHECK: fcmp oge float
+  // NATIVE-HALF: fcmp oge half
   test = (h0 >= h2);
   // CHECK: [[F16TOF32]]
   // NOHALF: [[F16TOF32]]
-  // CHECK: fcmp oge
+  // CHECK: fcmp oge float
+  // NATIVE-HALF: fcmp oge half
   test = (h0 >= (__fp16)-2.0);
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp oge
+  // CHECK: fcmp oge float
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fcmp oge float
   test = (h0 >= f2);
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp oge
+  // CHECK: fcmp oge float
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fcmp oge float
   test = (f0 >= h2);
 
   // CHECK: [[F16TOF32]]
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp oeq
+  // CHECK: fcmp oeq float
+  // NATIVE-HALF: fcmp oeq half
   test = (h1 == h2);
   // CHECK: [[F16TOF32]]
   // NOHALF: [[F16TOF32]]
-  // CHECK: fcmp oeq
+  // CHECK: fcmp oeq float
+  // NATIVE-HALF: fcmp oeq half
   test = (h1 == (__fp16)1.0);
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp oeq
+  // CHECK: fcmp oeq float
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fcmp oeq float
   test = (h1 == f1);
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp oeq
+  // CHECK: fcmp oeq float
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fcmp oeq float
   test = (f1 == h1);
 
   // CHECK: [[F16TOF32]]
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp une
+  // CHECK: fcmp une float
+  // NATIVE-HALF: fcmp une half
   test = (h1 != h2);
   // CHECK: [[F16TOF32]]
   // NOHALF: [[F16TOF32]]
-  // CHECK: fcmp une
+  // CHECK: fcmp une float
+  // NATIVE-HALF: fcmp une half
   test = (h1 != (__fp16)1.0);
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp une
+  // CHECK: fcmp une float
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fcmp une float
   test = (h1 != f1);
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp une
+  // CHECK: fcmp une float
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fcmp une float
   test = (f1 != h1);
 
   // CHECK: [[F16TOF32]]
-  // CHECK: fcmp une
+  // CHECK: fcmp une float
   // CHECK: [[F16TOF32]]
   // CHECK: [[F16TOF32]]
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fcmp une half {{.*}}, 0xH0000
   h1 = (h1 ? h2 : h0);
   // Check assignments (inc. compound)
   h0 = h1;
   // NOHALF: [[F32TOF16]]
   // HALF: store {{.*}} half 0xHC000
+  // NATIVE-HALF: store {{.*}} half 0xHC000
   h0 = (__fp16)-2.0f;
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fptrunc float
   h0 = f0;
 
   // CHECK: [[F16TOF32]]
   // CHECK: [[F16TOF32]]
   // CHECK: fadd float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fadd half
   h0 += h1;
   // CHECK: [[F16TOF32]]
   // NOHALF: [[F16TOF32]]
-  // CHECK: fadd
+  // CHECK: fadd float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fadd half
   h0 += (__fp16)1.0f;
   // CHECK: [[F16TOF32]]
-  // CHECK: fadd
+  // CHECK: fadd float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fadd float
+  // NATIVE-HALF: fptrunc float
   h0 += f2;
 
   // CHECK: [[F16TOF32]]
   // CHECK: [[F16TOF32]]
-  // CHECK: fsub
+  // CHECK: fsub float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fsub half
   h0 -= h1;
   // CHECK: [[F16TOF32]]
   // NOHALF: [[F16TOF32]]
-  // CHECK: fsub
+  // CHECK: fsub float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fsub half
   h0 -= (__fp16)1.0;
   // CHECK: [[F16TOF32]]
-  // CHECK: fsub
+  // CHECK: fsub float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fsub float
+  // NATIVE-HALF: fptrunc float
   h0 -= f2;
 
   // CHECK: [[F16TOF32]]
   // CHECK: [[F16TOF32]]
-  // CHECK: fmul
+  // CHECK: fmul float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fmul half
   h0 *= h1;
   // CHECK: [[F16TOF32]]
   // NOHALF: [[F16TOF32]]
-  // CHECK: fmul
+  // CHECK: fmul float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fmul half
   h0 *= (__fp16)1.0;
   // CHECK: [[F16TOF32]]
-  // CHECK: fmul
+  // CHECK: fmul float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fmul float
+  // NATIVE-HALF: fptrunc float
   h0 *= f2;
 
   // CHECK: [[F16TOF32]]
   // CHECK: [[F16TOF32]]
-  // CHECK: fdiv
+  // CHECK: fdiv float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fdiv half
   h0 /= h1;
   // CHECK: [[F16TOF32]]
   // NOHALF: [[F16TOF32]]
-  // CHECK: fdiv
+  // CHECK: fdiv float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fdiv half
   h0 /= (__fp16)1.0;
   // CHECK: [[F16TOF32]]
-  // CHECK: fdiv
+  // CHECK: fdiv float
   // CHECK: [[F32TOF16]]
+  // NATIVE-HALF: fpext half
+  // NATIVE-HALF: fdiv float
+  // NATIVE-HALF: fptrunc float
   h0 /= f2;
 
   // Check conversions to/from double
   // NOHALF: call i16 @llvm.convert.to.fp16.f64(
   // HALF: fptrunc double {{.*}} to half
+  // NATIVE-HALF: fptrunc double {{.*}} to half
   h0 = d0;
 
   // CHECK: [[MID:%.*]] = fptrunc double {{%.*}} to float
   // NOHALF: call i16 @llvm.convert.to.fp16.f32(float [[MID]])
   // HALF: fptrunc float [[MID]] to half
+  // NATIVE-HALF: [[MID:%.*]] = fptrunc double {{%.*}} to float
+  // NATIVE-HALF: fptrunc float {{.*}} to half
   h0 = (float)d0;
 
   // NOHALF: call double @llvm.convert.from.fp16.f64(
   // HALF: fpext half {{.*}} to double
+  // NATIVE-HALF: fpext half {{.*}} to double
   d0 = h0;
 
   // NOHALF: [[MID:%.*]] = call float @llvm.convert.from.fp16.f32(
   // HALF: [[MID:%.*]] = fpext half {{.*}} to float
   // CHECK: fpext float [[MID]] to double
+  // NATIVE-HALF: [[MID:%.*]] = fpext half {{.*}} to float
+  // NATIVE-HALF: fpext float [[MID]] to double
   d0 = (float)h0;
 }