clang/test/CodeGen/fp-contract-on-pragma.cpp

   1 // RUN: %clang_cc1 -O3 -triple %itanium_abi_triple -emit-llvm -o - %s | FileCheck %s
   2
   3 // Is FP_CONTRACT honored in a simple case?
   4 float fp_contract_1(float a, float b, float c) {
   5 // CHECK: _Z13fp_contract_1fff
   6 // CHECK: tail call float @llvm.fmuladd
   7 #pragma clang fp contract(on)
   8   return a * b + c;
   9 }
  10
  11 // Is FP_CONTRACT state cleared on exiting compound statements?
  12 float fp_contract_2(float a, float b, float c) {
  13   // CHECK: _Z13fp_contract_2fff
  14   // CHECK: %[[M:.+]] = fmul float %a, %b
  15   // CHECK-NEXT: fadd float %[[M]], %c
  16   {
  17 #pragma clang fp contract(on)
  18   }
  19   return a * b + c;
  20 }
  21
  22 // Does FP_CONTRACT survive template instantiation?
  23 class Foo {};
  24 Foo operator+(Foo, Foo);
  25
  26 template <typename T>
  27 T template_muladd(T a, T b, T c) {
  28 #pragma clang fp contract(on)
  29   return a * b + c;
  30 }
  31
  32 float fp_contract_3(float a, float b, float c) {
  33   // CHECK: _Z13fp_contract_3fff
  34   // CHECK: tail call noundef float @llvm.fmuladd
  35   return template_muladd<float>(a, b, c);
  36 }
  37
  38 template <typename T>
  39 class fp_contract_4 {
  40   float method(float a, float b, float c) {
  41 #pragma clang fp contract(on)
  42     return a * b + c;
  43   }
  44 };
  45
  46 template class fp_contract_4<int>;
  47 // CHECK: _ZN13fp_contract_4IiE6methodEfff
  48 // CHECK: tail call float @llvm.fmuladd
  49
  50 // Check file-scoped FP_CONTRACT
  51 #pragma clang fp contract(on)
  52 float fp_contract_5(float a, float b, float c) {
  53   // CHECK: _Z13fp_contract_5fff
  54   // CHECK: tail call float @llvm.fmuladd
  55   return a * b + c;
  56 }
  57
  58 #pragma clang fp contract(off)
  59 float fp_contract_6(float a, float b, float c) {
  60   // CHECK: _Z13fp_contract_6fff
  61   // CHECK: %[[M:.+]] = fmul float %a, %b
  62   // CHECK-NEXT: fadd float %[[M]], %c
  63   return a * b + c;
  64 }
  65
  66 // If the multiply has multiple uses, don't produce fmuladd.
  67 // This used to assert (PR25719):
  68 // https://llvm.org/bugs/show_bug.cgi?id=25719
  69
  70 float fp_contract_7(float a, float b, float c) {
  71 // CHECK: _Z13fp_contract_7fff
  72 // CHECK:  %[[M:.+]] = fmul float %b, 2.000000e+00
  73 // CHECK-NEXT: fsub float %[[M]], %c
  74 #pragma clang fp contract(on)
  75   return (a = 2 * b) - c;
  76 }