bbf0d1932a
FLT_EVAL_METHOD tells the user the precision at which, temporary results are evaluated but when fast-math is enabled, the numeric values are not guaranteed to match the source semantics, so the eval-method is meaningless. For example, the expression `x + y + z` has as source semantics `(x + y) + z`. FLT_EVAL_METHOD is telling the user at which precision `(x + y)` is evaluated. With fast-math enable the compiler can choose to evaluate the expression as `(y + z) + x`. The correct behavior is to set the FLT_EVAL_METHOD to `-1` to tell the user that the precision of the intermediate values is unknow. This patch is doing that. Differential Revision: https://reviews.llvm.org/D121122
118 lines
3.1 KiB
C++
118 lines
3.1 KiB
C++
// RUN: %clang_cc1 -fexperimental-strict-floating-point \
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// RUN: -triple x86_64-linux-gnu -emit-llvm -o - %s \
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// RUN: | FileCheck %s -check-prefixes=CHECK
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// RUN: %clang_cc1 -triple i386--linux -emit-llvm -o - %s \
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// RUN: | FileCheck %s -check-prefixes=CHECK-EXT
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// RUN: %clang_cc1 -fexperimental-strict-floating-point \
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// RUN: -mreassociate -freciprocal-math -ffp-contract=fast \
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// RUN: -ffast-math -triple x86_64-linux-gnu \
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// RUN: -emit-llvm -o - %s \
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// RUN: | FileCheck %s -check-prefixes=CHECK-FAST
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// RUN: %clang_cc1 -triple i386--linux -mreassociate -freciprocal-math \
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// RUN: -ffp-contract=fast -ffast-math -emit-llvm -o - %s \
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// RUN: | FileCheck %s -check-prefixes=CHECK-FAST
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float a = 1.0f, b = 2.0f, c = 3.0f;
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#pragma float_control(precise, off)
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float res2 = a + b + c;
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int val3 = __FLT_EVAL_METHOD__;
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#pragma float_control(precise, on)
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float res3 = a + b + c;
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int val4 = __FLT_EVAL_METHOD__;
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// CHECK: @val3 = global i32 -1
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// CHECK: @val4 = global i32 0
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// CHECK-EXT: @val3 = global i32 -1
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// CHECK-EXT: @val4 = global i32 2
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// CHECK-FAST: @val3 = global i32 -1
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// CHECK-FAST: @val4 = global i32 -1
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float res;
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int add(float a, float b, float c) {
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// CHECK: fadd float
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// CHECK: load float, float*
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// CHECK: fadd float
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// CHECK: store float
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// CHECK: ret i32 0
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res = a + b + c;
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return __FLT_EVAL_METHOD__;
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}
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int add_precise(float a, float b, float c) {
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#pragma float_control(precise, on)
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// CHECK: fadd float
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// CHECK: load float, float*
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// CHECK: fadd float
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// CHECK: store float
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// CHECK: ret i32 0
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res = a + b + c;
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return __FLT_EVAL_METHOD__;
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}
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#pragma float_control(push)
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#pragma float_control(precise, on)
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int add_precise_1(float a, float b, float c) {
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// CHECK: fadd float
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// CHECK: load float, float*
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// CHECK: fadd float
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// CHECK: store float
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// CHECK: ret i32 0
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res = a + b + c;
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return __FLT_EVAL_METHOD__;
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}
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#pragma float_control(pop)
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int add_not_precise(float a, float b, float c) {
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// Fast-math is enabled with this pragma.
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#pragma float_control(precise, off)
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// CHECK: fadd fast float
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// CHECK: load float, float*
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// CHECK: fadd fast float
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// CHECK: float {{.*}}, float*
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// CHECK: ret i32 -1
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res = a + b + c;
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return __FLT_EVAL_METHOD__;
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}
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#pragma float_control(push)
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// Fast-math is enabled with this pragma.
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#pragma float_control(precise, off)
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int add_not_precise_1(float a, float b, float c) {
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// CHECK: fadd fast float
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// CHECK: load float, float*
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// CHECK: fadd fast float
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// CHECK: float {{.*}}, float*
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// CHECK: ret i32 -1
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res = a + b + c;
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return __FLT_EVAL_METHOD__;
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}
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#pragma float_control(pop)
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int getFPEvalMethod() {
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// CHECK: ret i32 0
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return __FLT_EVAL_METHOD__;
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}
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float res1;
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int whatever(float a, float b, float c) {
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#pragma float_control(precise, off)
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// CHECK: load float, float*
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// CHECK: fadd fast float
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// CHECK: store float {{.*}}, float*
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// CHECK: store i32 -1
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// CHECK: store i32 0
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// CHECK: ret i32 -1
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res1 = a + b + c;
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int val1 = __FLT_EVAL_METHOD__;
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{
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#pragma float_control(precise, on)
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int val2 = __FLT_EVAL_METHOD__;
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}
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return __FLT_EVAL_METHOD__;
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}
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