clang/test/CodeGen/fp-floatcontrol-pragma.cpp

// RUN: %clang_cc1 -DEXCEPT=1 -fcxx-exceptions -triple x86_64-linux-gnu -emit-llvm -o - %s | FileCheck -check-prefix=CHECK-NS %s
// RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm -o - %s | FileCheck %s
// RUN: %clang_cc1 -verify -DFENV_ON=1 -triple x86_64-linux-gnu -emit-llvm -o - %s | FileCheck %s

float fff(float x, float y) {
// CHECK-LABEL: define float @_Z3fffff{{.*}}
// CHECK: entry
#pragma float_control(except, on)
  float z;
  z = z * z;
  //CHECK: llvm.experimental.constrained.fmul{{.*}}
  {
    z = x * y;
    //CHECK: llvm.experimental.constrained.fmul{{.*}}
  }
  {
// This pragma has no effect since if there are any fp intrin in the
// function then all the operations need to be fp intrin
#pragma float_control(except, off)
    z = z + x * y;
    //CHECK: llvm.experimental.constrained.fmul{{.*}}
  }
  z = z * z;
  //CHECK: llvm.experimental.constrained.fmul{{.*}}
  return z;
}
float check_precise(float x, float y) {
  // CHECK-LABEL: define float @_Z13check_preciseff{{.*}}
  float z;
  {
#pragma float_control(precise, on)
    z = x * y + z;
    //CHECK: llvm.fmuladd{{.*}}
  }
  {
#pragma float_control(precise, off)
    z = x * y + z;
    //CHECK: fmul fast float
    //CHECK: fadd fast float
  }
  return z;
}

float fma_test1(float a, float b, float c) {
// CHECK-LABEL define float @_Z9fma_test1fff{{.*}}
#pragma float_control(precise, on)
  float x = a * b + c;
  //CHECK: fmuladd
  return x;
}

#if FENV_ON
// expected-warning@+1{{pragma STDC FENV_ACCESS ON is not supported, ignoring pragma}}
#pragma STDC FENV_ACCESS ON
#endif
// CHECK-LABEL: define {{.*}}callt{{.*}}

void callt() {
  volatile float z;
  z = z * z;
//CHECK: = fmul float
}

#if EXCEPT
namespace ns {
// Check that pragma float_control can appear in namespace.
#pragma float_control(except, on, push)
float exc_on(double x, float zero) {
// CHECK-NS: define {{.*}}exc_on{{.*}}
  {} try {
    x = 1.0 / zero; /* division by zero, the result unused */
//CHECK-NS: llvm.experimental.constrained.fdiv{{.*}}
  } catch (...) {}
  return zero;
}
}

// Check pragma is still effective after namespace closes
float exc_still_on(double x, float zero) {
// CHECK-NS: define {{.*}}exc_still_on{{.*}}
  {} try {
    x = 1.0 / zero; /* division by zero, the result unused */
//CHECK-NS: llvm.experimental.constrained.fdiv{{.*}}
  } catch (...) {}
  return zero;
}

#pragma float_control(pop)
float exc_off(double x, float zero) {
// CHECK-NS: define {{.*}}exc_off{{.*}}
  {} try {
    x = 1.0 / zero; /* division by zero, the result unused */
//CHECK-NS: fdiv contract double
  } catch (...) {}
  return zero;
}

namespace fc_template_namespace {
#pragma float_control(except, on, push)
template <class T>
T exc_on(double x, T zero) {
// CHECK-NS: define {{.*}}fc_template_namespace{{.*}}
  {} try {
    x = 1.0 / zero; /* division by zero, the result unused */
//CHECK-NS: llvm.experimental.constrained.fdiv{{.*}}
  } catch (...) {}
  return zero;
}
}

#pragma float_control(pop)
float xx(double x, float z) {
  return fc_template_namespace::exc_on<float>(x, z);
}
#endif // EXCEPT