clang/test/CodeGen/fp-contract-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 STDC 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 STDC 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 STDC 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 float @llvm.fmuladd
  35   return template_muladd<float>(a, b, c);
  36 }
  37
  38 template<typename T> class fp_contract_4 {
  39   float method(float a, float b, float c) {
  40     #pragma STDC FP_CONTRACT ON
  41     return a * b + c;
  42   }
  43 };
  44
  45 template class fp_contract_4<int>;
  46 // CHECK: _ZN13fp_contract_4IiE6methodEfff
  47 // CHECK: tail call float @llvm.fmuladd
  48
  49 // Check file-scoped FP_CONTRACT
  50 #pragma STDC FP_CONTRACT ON
  51 float fp_contract_5(float a, float b, float c) {
  52 // CHECK: _Z13fp_contract_5fff
  53 // CHECK: tail call float @llvm.fmuladd
  54   return a * b + c;
  55 }
  56
  57 #pragma STDC FP_CONTRACT OFF
  58 float fp_contract_6(float a, float b, float c) {
  59 // CHECK: _Z13fp_contract_6fff
  60 // CHECK: %[[M:.+]] = fmul float %a, %b
  61 // CHECK-NEXT: fadd float %[[M]], %c
  62   return a * b + c;
  63 }
  64
  65 // If the multiply has multiple uses, don't produce fmuladd.
  66 // This used to assert (PR25719):
  67 // https://llvm.org/bugs/show_bug.cgi?id=25719
  68
  69 float fp_contract_7(float a, float b, float c) {
  70 // CHECK: _Z13fp_contract_7fff
  71 // CHECK:  %[[M:.+]] = fmul float %b, 2.000000e+00
  72 // CHECK-NEXT: fsub float %[[M]], %c
  73   #pragma STDC FP_CONTRACT ON
  74   return (a = 2 * b) - c;
  75 }
  76
  77 float fp_contract_8(float a, float b, float c) {
  78 // CHECK: _Z13fp_contract_8fff
  79 // CHECK: fneg float %c
  80 // CHECK: tail call float @llvm.fmuladd
  81   #pragma STDC FP_CONTRACT ON
  82   return a * b - c;
  83 }
  84
  85 float fp_contract_9(float a, float b, float c) {
  86 // CHECK: _Z13fp_contract_9fff
  87 // CHECK: fneg float %a
  88 // CHECK: tail call float @llvm.fmuladd
  89   #pragma STDC FP_CONTRACT ON
  90   return c - a * b;
  91 }