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

   1 // RUN: %clang_cc1 -O3 -triple %itanium_abi_triple -emit-llvm -o - %s | FileCheck -check-prefixes=CHECK,DEFAULT %s
   2 // RUN: %clang_cc1 -O3 -triple %itanium_abi_triple -freciprocal-math -emit-llvm -o - %s | FileCheck -check-prefixes=CHECK,FLAG %s
   3
   4 float base(float a, float b, float c) {
   5 // CHECK-LABEL: _Z4basefff
   6 // FLAG: %[[A:.+]] = fdiv arcp float %b, %c
   7 // FLAG: %[[M:.+]] = fdiv arcp float %[[A]], %b
   8 // FLAG-NEXT: fadd arcp float %c, %[[M]]
   9
  10 // DEFAULT: %[[A:.+]] = fdiv float %b, %c
  11 // DEFAULT: %[[M:.+]] = fdiv float %[[A]], %b
  12 // DEFAULT-NEXT: fadd float %c, %[[M]]
  13   a = b / c;
  14   return a / b + c;
  15 }
  16
  17 // Simple case
  18 float fp_recip_simple(float a, float b, float c) {
  19 // CHECK-LABEL: _Z15fp_recip_simplefff
  20 // CHECK: %[[A:.+]] = fdiv arcp float %b, %c
  21 // CHECK: %[[M:.+]] = fdiv arcp float %[[A]], %b
  22 // CHECK-NEXT: fadd arcp float %c, %[[M]]
  23 #pragma clang fp reciprocal(on)
  24   a = b / c;
  25   return a / b + c;
  26 }
  27
  28 // Test interaction with -freciprocal-math
  29 float fp_recip_disable(float a, float b, float c) {
  30 // CHECK-LABEL: _Z16fp_recip_disablefff
  31 // CHECK: %[[A:.+]] = fdiv float %b, %c
  32 // CHECK: %[[M:.+]] = fdiv float %[[A]], %b
  33 // CHECK-NEXT: fadd float %c, %[[M]]
  34 #pragma clang fp reciprocal(off)
  35   a = b / c;
  36   return a / b + c;
  37 }
  38
  39 float fp_recip_with_reassoc_simple(float a, float b, float c) {
  40 // CHECK-LABEL: _Z28fp_recip_with_reassoc_simplefff
  41 // CHECK: %[[A:.+]] = fmul reassoc arcp float %b, %c
  42 // CHECK: %[[M:.+]] = fdiv reassoc arcp float %b, %[[A]]
  43 // CHECK-NEXT: fadd reassoc arcp float %c, %[[M]]
  44 #pragma clang fp reciprocal(on) reassociate(on)
  45   a = b / c;
  46   return a / b + c;
  47 }
  48
  49 // arcp pragma should only apply to its scope
  50 float fp_recip_scoped(float a, float b, float c) {
  51   // CHECK-LABEL: _Z15fp_recip_scopedfff
  52   // DEFAULT: %[[M:.+]] = fdiv float %a, %b
  53   // DEFAULT-NEXT: fadd float %[[M]], %c
  54   // FLAG: %[[M:.+]] = fdiv arcp float %a, %b
  55   // FLAG-NEXT: fadd arcp float %[[M]], %c
  56   {
  57 #pragma clang fp reciprocal(on)
  58   }
  59   return a / b + c;
  60 }
  61
  62 // arcp pragma should apply to templates as well
  63 class Foo {};
  64 Foo operator+(Foo, Foo);
  65 template <typename T>
  66 T template_recip(T a, T b, T c) {
  67 #pragma clang fp reciprocal(on)
  68   return ((a / b) - c) + c;
  69 }
  70
  71 float fp_recip_template(float a, float b, float c) {
  72   // CHECK-LABEL: _Z17fp_recip_templatefff
  73   // CHECK: %[[A1:.+]] = fdiv arcp float %a, %b
  74   // CHECK-NEXT: %[[A2:.+]] = fsub arcp float %[[A1]], %c
  75   // CHECK-NEXT: fadd arcp float %c, %[[A2]]
  76   return template_recip<float>(a, b, c);
  77 }
  78
  79 // File Scoping should work across functions
  80 #pragma clang fp reciprocal(on)
  81 float fp_file_scope_on(float a, float b, float c) {
  82   // CHECK-LABEL: _Z16fp_file_scope_onfff
  83   // CHECK: %[[M1:.+]] = fdiv arcp float %a, %c
  84   // CHECK-NEXT: %[[M2:.+]] = fdiv arcp float %b, %c
  85   // CHECK-NEXT: fadd arcp float %[[M1]], %[[M2]]
  86   return (a / c) + (b / c);
  87 }
  88
  89 // Inner pragma has precedence
  90 float fp_file_scope_stop(float a, float b, float c) {
  91   // CHECK-LABEL: _Z18fp_file_scope_stopfff
  92   // CHECK: %[[A:.+]] = fdiv arcp float %a, %a
  93   // CHECK: %[[M1:.+]] = fdiv float %[[A]], %c
  94   // CHECK-NEXT: %[[M2:.+]] = fdiv float %b, %c
  95   // CHECK-NEXT: fsub float %[[M1]], %[[M2]]
  96   a = a / a;
  97   {
  98 #pragma clang fp reciprocal(off)
  99     return (a / c) - (b / c);
 100   }
 101 }
 102
 103 #pragma clang fp reciprocal(off)
 104 float fp_recip_off(float a, float b, float c) {
 105   // CHECK-LABEL: _Z12fp_recip_offfff
 106   // CHECK: %[[D1:.+]] = fdiv float %a, %c
 107   // CHECK-NEXT: %[[D2:.+]] = fdiv float %b, %c
 108   // CHECK-NEXT: fadd float %[[D1]], %[[D2]]
 109   return (a / c) + (b / c);
 110 }
 111
 112 // Takes latest flag
 113 float fp_recip_many(float a, float b, float c) {
 114 // CHECK-LABEL: _Z13fp_recip_manyfff
 115 // CHECK: %[[D1:.+]] = fdiv arcp float %a, %c
 116 // CHECK-NEXT: %[[D2:.+]] = fdiv arcp float %b, %c
 117 // CHECK-NEXT: fadd arcp float %[[D1]], %[[D2]]
 118 #pragma clang fp reciprocal(off) reciprocal(on)
 119   return (a / c) + (b / c);
 120 }
 121
 122 // Pragma does not propagate through called functions
 123 float helper_func(float a, float b, float c) { return a + b + c; }
 124 float fp_recip_call_helper(float a, float b, float c) {
 125 // CHECK-LABEL: _Z20fp_recip_call_helperfff
 126 // CHECK: %[[S1:.+]] = fadd float %a, %b
 127 // CHECK-NEXT: fadd float %[[S1]], %c
 128 #pragma clang fp reciprocal(on)
 129   return helper_func(a, b, c);
 130 }