xref: /aosp_15_r20/external/llvm-libc/src/math/amdgpu/platform.h (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
1 //===-- AMDGPU specific platform definitions for math support -------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef LLVM_LIBC_SRC_MATH_AMDGPU_PLATFORM_H
10 #define LLVM_LIBC_SRC_MATH_AMDGPU_PLATFORM_H
11 
12 #include "src/__support/macros/attributes.h"
13 #include "src/__support/macros/config.h"
14 
15 #include <stdint.h>
16 
17 namespace LIBC_NAMESPACE_DECL {
18 
19 // The ROCm device library uses control globals to alter codegen for the
20 // different targets. To avoid needing to link them in manually we simply
21 // define them here.
22 extern "C" {
23 
24 // Disable unsafe math optimizations in the implementation.
25 extern const LIBC_INLINE_VAR uint8_t __oclc_unsafe_math_opt = 0;
26 
27 // Disable denormalization at zero optimizations in the implementation.
28 extern const LIBC_INLINE_VAR uint8_t __oclc_daz_opt = 0;
29 
30 // Disable rounding optimizations for 32-bit square roots.
31 extern const LIBC_INLINE_VAR uint8_t __oclc_correctly_rounded_sqrt32 = 1;
32 
33 // Disable finite math optimizations.
34 extern const LIBC_INLINE_VAR uint8_t __oclc_finite_only_opt = 0;
35 
36 // Set the ISA value to a high enough value that the ROCm device library math
37 // functions will assume we have fast FMA operations among other features. This
38 // is determined to be safe on all targets by looking at the source code.
39 // https://github.com/ROCm/ROCm-Device-Libs/blob/amd-stg-open/ocml/src/opts.h
40 extern const LIBC_INLINE_VAR uint32_t __oclc_ISA_version = 9000;
41 }
42 
43 // These aliases cause clang to emit the control constants with ODR linkage.
44 // This allows us to link against the symbols without preventing them from being
45 // optimized out or causing symbol collisions.
46 [[gnu::alias("__oclc_unsafe_math_opt")]] const uint8_t __oclc_unsafe_math_opt__;
47 [[gnu::alias("__oclc_daz_opt")]] const uint8_t __oclc_daz_opt__;
48 [[gnu::alias("__oclc_correctly_rounded_sqrt32")]] const uint8_t
49     __oclc_correctly_rounded_sqrt32__;
50 [[gnu::alias("__oclc_finite_only_opt")]] const uint8_t __oclc_finite_only_opt__;
51 [[gnu::alias("__oclc_ISA_version")]] const uint32_t __oclc_ISA_version__;
52 
53 } // namespace LIBC_NAMESPACE_DECL
54 
55 #endif // LLVM_LIBC_SRC_MATH_AMDGPU_PLATFORM_H
56