Make FP_CONTRACT ON default.

[scanon]

Summary

Now that we have reasonable support for FP_CONTRACT OFF, we can justify making FP_CONTRACT ON the default behavior.

[scanon]

Additionally test contraction of compound assignment expressions.

[hfinkel]

LGTM, thanks!

include/clang/Basic/LangOptions.def

 BENIGN_LANGOPT(ParseUnknownAnytype, 1, 0, "__unknown_anytype")
 BENIGN_LANGOPT(DebuggerSupport , 1, 0, "debugger support")
 BENIGN_LANGOPT(DebuggerCastResultToId, 1, 0, "for 'po' in the debugger, cast the result to id if it is of unknown type")
 BENIGN_LANGOPT(DebuggerObjCLiteral , 1, 0, "debugger Objective-C literals and subscripting support")
 
 BENIGN_LANGOPT(SpellChecking , 1, 1, "spell-checking")
 LANGOPT(SinglePrecisionConstants , 1, 0, "treating double-precision floating point constants as single precision constants")
 LANGOPT(FastRelaxedMath , 1, 0, "OpenCL fast relaxed math")
-LANGOPT(DefaultFPContract , 1, 0, "FP_CONTRACT")
+LANGOPT(DefaultFPContract , 1, 1, "FP_CONTRACT")
 LANGOPT(NoBitFieldTypeAlign , 1, 0, "bit-field type alignment")
 LANGOPT(HexagonQdsp6Compat , 1, 0, "hexagon-qdsp6 backward compatibility")
 LANGOPT(ObjCAutoRefCount , 1, 0, "Objective-C automated reference counting")
 LANGOPT(ObjCWeakRuntime     , 1, 0, "__weak support in the ARC runtime")
 LANGOPT(ObjCWeak            , 1, 0, "Objective-C __weak in ARC and MRC files")
 LANGOPT(ObjCSubscriptingLegacyRuntime         , 1, 0, "Subscripting support in legacy ObjectiveC runtime")
 LANGOPT(FakeAddressSpaceMap , 1, 0, "OpenCL fake address space map")
 ENUM_LANGOPT(AddressSpaceMapMangling , AddrSpaceMapMangling, 2, ASMM_Target, "OpenCL address space map mangling mode")

lib/Frontend/CompilerInvocation.cpp

else if (LangStd == LangStandard::lang_opencl20)
     Opts.OpenCLVersion = 200;
 
   // OpenCL has some additional defaults.
   if (Opts.OpenCL) {
     Opts.AltiVec = 0;
     Opts.ZVector = 0;
     Opts.CXXOperatorNames = 1;
     Opts.LaxVectorConversions = 0;
-    Opts.DefaultFPContract = 1;
     Opts.NativeHalfType = 1;
   }
 
   Opts.CUDA = IK == IK_CUDA || IK == IK_PreprocessedCuda ||
               LangStd == LangStandard::lang_cuda;
 
   // OpenCL and C++ both have bool, true, false keywords.
   Opts.Bool = Opts.OpenCL || Opts.CPlusPlus;

test/CodeGen/aarch64-neon-fma.c

 // REQUIRES: aarch64-registered-target
-// RUN: %clang_cc1 -triple arm64-none-linux-gnu -target-feature +neon -S -O3 -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple arm64-none-linux-gnu -target-feature +neon -S -O3 \
+// RUN:   -ffp-contract=off -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple arm64-none-linux-gnu -target-feature +neon -S -O3 \
+// RUN:   -o - %s | FileCheck -check-prefix=CHECK-FMA %s
 
 // Test new aarch64 intrinsics and types
 
 #include <arm_neon.h>
 
 float32x2_t test_vmla_n_f32(float32x2_t a, float32x2_t b, float32_t c) {
   // CHECK-LABEL: test_vmla_n_f32
   return vmla_n_f32(a, b, c);
   // CHECK: fmul {{v[0-9]+}}.2s, {{v[0-9]+}}.2s, {{v[0-9]+}}.s[0]
   // CHECK: fadd {{v[0-9]+}}.2s, {{v[0-9]+}}.2s, {{v[0-9]+}}.2s
-  // CHECK-FMA: dup {{v[0-9]+}}.2s, {{v[0-9]+}}.s[0]
-  // CHECK-FMA: fmla {{v[0-9]+}}.2s, {{v[0-9]+}}.2s, {{v[0-9]+}}.2s
+  // CHECK-FMA: fmla {{v[0-9]+}}.2s, {{v[0-9]+}}.2s, {{v[0-9]+}}.s[0]
 }
 
 float32x4_t test_vmlaq_n_f32(float32x4_t a, float32x4_t b, float32_t c) {
   // CHECK-LABEL: test_vmlaq_n_f32
   return vmlaq_n_f32(a, b, c);
   // CHECK: fmul {{v[0-9]+}}.4s, {{v[0-9]+}}.4s, {{v[0-9]+}}.s[0]
   // CHECK: fadd {{v[0-9]+}}.4s, {{v[0-9]+}}.4s, {{v[0-9]+}}.4s
-  // CHECK-FMA: dup {{v[0-9]+}}.4s, {{v[0-9]+}}.s[0]
-  // CHECK-FMA: fmla {{v[0-9]+}}.4s, {{v[0-9]+}}.4s, {{v[0-9]+}}.4s
+  // CHECK-FMA: fmla {{v[0-9]+}}.4s, {{v[0-9]+}}.4s, {{v[0-9]+}}.s[0]
 }
 
 float64x2_t test_vmlaq_n_f64(float64x2_t a, float64x2_t b, float64_t c) {
   // CHECK-LABEL: test_vmlaq_n_f64
   return vmlaq_n_f64(a, b, c);
   // CHECK: fmul {{v[0-9]+}}.2d, {{v[0-9]+}}.2d, {{v[0-9]+}}.d[0]
   // CHECK: fadd {{v[0-9]+}}.2d, {{v[0-9]+}}.2d, {{v[0-9]+}}.2d
-  // CHECK-FMA: dup {{v[0-9]+}}.2d, {{v[0-9]+}}.d[0]
-  // CHECK-FMA: fmla {{v[0-9]+}}.2d, {{v[0-9]+}}.2d, {{v[0-9]+}}.2d
+  // CHECK-FMA: fmla {{v[0-9]+}}.2d, {{v[0-9]+}}.2d, {{v[0-9]+}}.d[0]
 }
 
 float32x4_t test_vmlsq_n_f32(float32x4_t a, float32x4_t b, float32_t c) {
   // CHECK-LABEL: test_vmlsq_n_f32
   return vmlsq_n_f32(a, b, c);
   // CHECK: fmul {{v[0-9]+}}.4s, {{v[0-9]+}}.4s, {{v[0-9]+}}.s[0]
   // CHECK: fsub {{v[0-9]+}}.4s, {{v[0-9]+}}.4s, {{v[0-9]+}}.4s
-  // CHECK-FMA: dup {{v[0-9]+}}.4s, {{v[0-9]+}}.s[0]
-  // CHECK-FMA: fmls {{v[0-9]+}}.4s, {{v[0-9]+}}.4s, {{v[0-9]+}}.4s
+  // CHECK-FMA: fmls {{v[0-9]+}}.4s, {{v[0-9]+}}.4s, {{v[0-9]+}}.s[0]
 }
 
 float32x2_t test_vmls_n_f32(float32x2_t a, float32x2_t b, float32_t c) {
   // CHECK-LABEL: test_vmls_n_f32
   return vmls_n_f32(a, b, c);
   // CHECK: fmul {{v[0-9]+}}.2s, {{v[0-9]+}}.2s, {{v[0-9]+}}.s[0]
   // CHECK: fsub {{v[0-9]+}}.2s, {{v[0-9]+}}.2s, {{v[0-9]+}}.2s
-  // CHECK-FMA: dup {{v[0-9]+}}.2s, {{v[0-9]+}}.s[0]
-  // CHECK-FMA: fmls {{v[0-9]+}}.2s, {{v[0-9]+}}.2s, {{v[0-9]+}}.2s
+  // CHECK-FMA: fmls {{v[0-9]+}}.2s, {{v[0-9]+}}.2s, {{v[0-9]+}}.s[0]
 }
 
 float64x2_t test_vmlsq_n_f64(float64x2_t a, float64x2_t b, float64_t c) {
   // CHECK-LABEL: test_vmlsq_n_f64
   return vmlsq_n_f64(a, b, c);
   // CHECK: fmul {{v[0-9]+}}.2d, {{v[0-9]+}}.2d, {{v[0-9]+}}.d[0]
   // CHECK: fsub {{v[0-9]+}}.2d, {{v[0-9]+}}.2d, {{v[0-9]+}}.2d
-  // CHECK-FMA: dup {{v[0-9]+}}.2d, {{v[0-9]+}}.d[0]
-  // CHECK-FMA: fmls {{v[0-9]+}}.2d, {{v[0-9]+}}.2d, {{v[0-9]+}}.2d
+  // CHECK-FMA: fmls {{v[0-9]+}}.2d, {{v[0-9]+}}.2d, {{v[0-9]+}}.d[0]
 }
 
 float32x2_t test_vmla_lane_f32_0(float32x2_t a, float32x2_t b, float32x2_t v) {
   // CHECK-LABEL: test_vmla_lane_f32_0
   return vmla_lane_f32(a, b, v, 0);
   // CHECK: fmul {{v[0-9]+}}.2s, {{v[0-9]+}}.2s, {{v[0-9]+}}.s[0]
   // CHECK: fadd {{v[0-9]+}}.2s, {{v[0-9]+}}.2s, {{v[0-9]+}}.2s
   // CHECK-FMA: fmla {{v[0-9]+}}.2s, {{v[0-9]+}}.2s, {{v[0-9]+}}.s[0]

test/CodeGen/arm64-fma.c

+// RUN: %clang_cc1 -triple=aarch64-unknown -Os -ffp-contract=fast -S -o - %s | FileCheck -check-prefix=CHECK-FAST -check-prefix=CHECK-ALL %s
+// RUN: %clang_cc1 -triple=aarch64-unknown -Os -ffp-contract=on -S -o - %s | FileCheck -check-prefix=CHECK-ON -check-prefix=CHECK-ALL %s
+// RUN: %clang_cc1 -triple=aarch64-unknown -Os -ffp-contract=off -S -o - %s | FileCheck -check-prefix=CHECK-OFF -check-prefix=CHECK-ALL %s
+// RUN: %clang_cc1 -triple=aarch64-unknown -Os -S -o - %s | FileCheck -check-prefix=CHECK-ON -check-prefix=CHECK-ALL %s
+// REQUIRES: aarch64-registered-target
+
+float test1(float x, float y, float z) {
+  return x*y + z;
+  // CHECK-ALL-LABEL: test1:
+  // CHECK-FAST: fmadd
+  // CHECK-ON: fmadd
+  // CHECK-OFF: fmul
+  // CHECK-OFF-NEXT: fadd
+}
+
+double test2(double x, double y, double z) {
+  return x*y - z;
+  // CHECK-ALL-LABEL: test2:
+  // CHECK-FAST: fnmsub
+  // CHECK-ON: fnmsub
+  // CHECK-OFF: fmul
+  // CHECK-OFF-NEXT: fsub
+}
+
+float test3(float x, float y, float z) {
+  float tmp = x*y;
+  return tmp + z;
+  // CHECK-ALL-LABEL: test3:
+  // CHECK-FAST: fmadd
+  // CHECK-ON: fmul
+  // CHECK-ON-NEXT: fadd
+  // CHECK-OFF: fmul
+  // CHECK-OFF-NEXT: fadd
+}
+
+double test4(double x, double y, double z) {
+  double tmp = x*y;
+  return tmp - z;
+  // CHECK-ALL-LABEL: test4:
+  // CHECK-FAST: fnmsub
+  // CHECK-ON: fmul
+  // CHECK-ON-NEXT: fsub
+  // CHECK-OFF: fmul
+  // CHECK-OFF-NEXT: fsub
+}
+
+#pragma STDC FP_CONTRACT ON
+
+float test5(float x, float y, float z) {
+  return x*y + z;
+  // CHECK-ALL-LABEL: test5:
+  // CHECK-FAST: fmadd
+  // CHECK-ON: fmadd
+  // CHECK-OFF: fmul
+  // CHECK-OFF-NEXT: fadd
+}
+
+double test6(double x, double y, double z) {
+  return x*y - z;
+  // CHECK-ALL-LABEL: test6:
+  // CHECK-FAST: fnmsub
+  // CHECK-ON: fnmsub
+  // CHECK-OFF: fmul
+  // CHECK-OFF-NEXT: fsub
+}
+
+float test7(float x, float y, float z) {
+  float tmp = x*y;
+  return tmp + z;
+  // CHECK-ALL-LABEL: test7:
+  // CHECK-FAST: fmadd
+  // CHECK-ON: fmul
+  // CHECK-ON-NEXT: fadd
+  // CHECK-OFF: fmul
+  // CHECK-OFF-NEXT: fadd
+}
+
+double test8(double x, double y, double z) {
+  double tmp = x*y;
+  return tmp - z;
+  // CHECK-ALL-LABEL: test8:
+  // CHECK-FAST: fnmsub
+  // CHECK-ON: fmul
+  // CHECK-ON-NEXT: fsub
+  // CHECK-OFF: fmul
+  // CHECK-OFF-NEXT: fsub
+}
+
+#pragma STDC FP_CONTRACT OFF
+
+float test9(float x, float y, float z) {
+  return x*y + z;
+  // CHECK-ALL-LABEL: test9:
+  // CHECK-FAST: fmadd
+  // CHECK-ON: fmul
+  // CHECK-ON-NEXT: fadd
+  // CHECK-OFF: fmul
+  // CHECK-OFF-NEXT: fadd
+}
+
+double test10(double x, double y, double z) {
+  return x*y - z;
+  // CHECK-ALL-LABEL: test10:
+  // CHECK-FAST: fnmsub
+  // CHECK-ON: fmul
+  // CHECK-ON-NEXT: fsub
+  // CHECK-OFF: fmul
+  // CHECK-OFF-NEXT: fsub
+}
+
+float test11(float x, float y, float z) {
+  float tmp = x*y;
+  return tmp + z;
+  // CHECK-ALL-LABEL: test11:
+  // CHECK-FAST: fmadd
+  // CHECK-ON: fmul
+  // CHECK-ON-NEXT: fadd
+  // CHECK-OFF: fmul
+  // CHECK-OFF-NEXT: fadd
+}
+
+double test12(double x, double y, double z) {
+  double tmp = x*y;
+  return tmp - z;
+  // CHECK-ALL-LABEL: test12:
+  // CHECK-FAST: fnmsub
+  // CHECK-ON: fmul
+  // CHECK-ON-NEXT: fsub
+  // CHECK-OFF: fmul
+  // CHECK-OFF-NEXT: fsub
+}
+
+#pragma STDC FP_CONTRACT DEFAULT
+
+float test17(float x, float y, float z) {
+  return x*y + z;
+  // CHECK-ALL-LABEL: test17:
+  // CHECK-FAST: fmadd
+  // CHECK-ON: fmadd
+  // CHECK-OFF: fmul
+  // CHECK-OFF-NEXT: fadd
+}
+
+double test18(double x, double y, double z) {
+  return x*y - z;
+  // CHECK-ALL-LABEL: test18:
+  // CHECK-FAST: fnmsub
+  // CHECK-ON: fnmsub
+  // CHECK-OFF: fmul
+  // CHECK-OFF-NEXT: fsub
+}
+
+float test19(float x, float y, float z) {
+  float tmp = x*y;
+  return tmp + z;
+  // CHECK-ALL-LABEL: test19:
+  // CHECK-FAST: fmadd
+  // CHECK-ON: fmul
+  // CHECK-ON-NEXT: fadd
+  // CHECK-OFF: fmul
+  // CHECK-OFF-NEXT: fadd
+}
+
+double test20(double x, double y, double z) {
+  double tmp = x*y;
+  return tmp - z;
+  // CHECK-ALL-LABEL: test20:
+  // CHECK-FAST: fnmsub
+  // CHECK-ON: fmul
+  // CHECK-ON-NEXT: fsub
+  // CHECK-OFF: fmul
+  // CHECK-OFF-NEXT: fsub
+}

test/CodeGen/fp-contract-pragma.cpp

 // RUN: %clang_cc1 -O3 -triple %itanium_abi_triple -emit-llvm -o - %s | FileCheck %s
 
+#pragma STDC FP_CONTRACT OFF
+
 // Is FP_CONTRACT is honored in a simple case?
 float fp_contract_1(float a, float b, float c) {
 // CHECK: _Z13fp_contract_1fff
 // CHECK: tail call float @llvm.fmuladd
   #pragma STDC FP_CONTRACT ON
   return a * b + c;
 }
 

test/Driver/clang_f_opts.c

 // RUN: %clang -### -c %s 2>&1 | FileCheck -check-prefix=DEPRECATED-OFF-CHECK %s
 // RUN: %clang -### -c -Wdeprecated %s 2>&1 | FileCheck -check-prefix=DEPRECATED-OFF-CHECK %s
 // DEPRECATED-ON-CHECK: -fdeprecated-macro
 // DEPRECATED-OFF-CHECK-NOT: -fdeprecated-macro
 
 // RUN: %clang -### -S -ffp-contract=fast %s 2>&1 | FileCheck -check-prefix=FP-CONTRACT-FAST-CHECK %s
 // RUN: %clang -### -S -ffast-math %s 2>&1 | FileCheck -check-prefix=FP-CONTRACT-FAST-CHECK %s
 // RUN: %clang -### -S -ffp-contract=off %s 2>&1 | FileCheck -check-prefix=FP-CONTRACT-OFF-CHECK %s
+// RUN: %clang -### -S -ffp-contract=on %s 2>&1 | FileCheck -check-prefix=FP-CONTRACT-ON-CHECK %s
 // FP-CONTRACT-FAST-CHECK: -ffp-contract=fast
 // FP-CONTRACT-OFF-CHECK: -ffp-contract=off
+// FP-CONTRACT-ON-CHECK: -ffp-contract=on
 
 // RUN: %clang -### -S -funroll-loops %s 2>&1 | FileCheck -check-prefix=CHECK-UNROLL-LOOPS %s
 // RUN: %clang -### -S -fno-unroll-loops %s 2>&1 | FileCheck -check-prefix=CHECK-NO-UNROLL-LOOPS %s
 // RUN: %clang -### -S -fno-unroll-loops -funroll-loops %s 2>&1 | FileCheck -check-prefix=CHECK-UNROLL-LOOPS %s
 // RUN: %clang -### -S -funroll-loops -fno-unroll-loops %s 2>&1 | FileCheck -check-prefix=CHECK-NO-UNROLL-LOOPS %s
 // CHECK-UNROLL-LOOPS: "-funroll-loops"
 // CHECK-NO-UNROLL-LOOPS: "-fno-unroll-loops"