[libclc] Use float sw_fma for spirv*-mesa-mesa3d targets (#199626)

This partially reverts 39f3d72b72, which changes almost all targets to
use __builtin_elementwise_fma.
The same revert was done for clspv in 1d719edd99.

Restore __clc_runtime_has_hw_fma32 so that Mesa can dynamically change
its behavior to enable native fma for specific hardware.

Fixes #198542

libclc/clc/include/clc/internal/math/clc_runtime_has_hw_fma32.h

@@ -0,0 +1,16 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __CLC_INTERNAL_MATH_CLC_RUNTIME_HAS_HW_FMA32_H__
+#define __CLC_INTERNAL_MATH_CLC_RUNTIME_HAS_HW_FMA32_H__
+
+#include "clc/internal/clc.h"
+
+_CLC_DECL bool __attribute__((noinline)) __clc_runtime_has_hw_fma32(void);
+
+#endif // __CLC_INTERNAL_MATH_CLC_RUNTIME_HAS_HW_FMA32_H__

libclc/clc/include/clc/internal/math/clc_sw_fma.h

@@ -9,6 +9,8 @@
 #ifndef __CLC_INTERNAL_MATH_CLC_SW_FMA_H__
 #define __CLC_INTERNAL_MATH_CLC_SW_FMA_H__
 
+#include "clc/internal/clc.h"
+
 #define __CLC_FUNCTION __clc_sw_fma
 #define __CLC_FLOAT_ONLY
 #define __CLC_BODY "clc/shared/ternary_decl.inc"

libclc/clc/include/clc/math/clc_fma.h

@@ -9,6 +9,8 @@
 #ifndef __CLC_MATH_CLC_FMA_H__
 #define __CLC_MATH_CLC_FMA_H__
 
+#include "clc/internal/clc.h"
+
 #define __CLC_FUNCTION __clc_fma
 #define __CLC_BODY "clc/shared/ternary_decl.inc"
 

libclc/clc/lib/generic/math/clc_fma.cl

@@ -6,9 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clc/internal/clc.h"
 #include "clc/math/clc_fma.h"
-#include "clc/math/math.h"
 
 #define __CLC_FUNCTION __clc_fma
 #define __CLC_IMPL_FUNCTION(x) __builtin_elementwise_fma

libclc/clc/lib/spirv/CMakeLists.txt

@@ -3,7 +3,10 @@ if(LIBCLC_TARGET_OS AND EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBCLC_TARGET_OS})
 endif()
 
 libclc_add_sources(${LIBCLC_CLC_TARGET} FILES
+  math/clc_fma.cl
   math/clc_fmax.cl
   math/clc_fmin.cl
+  math/clc_runtime_has_hw_fma32.cl
+  math/clc_sw_fma.cl
   subnormal_config.cl
 )

libclc/clc/lib/spirv/math/clc_fma.cl

@@ -0,0 +1,15 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "clc/internal/math/clc_runtime_has_hw_fma32.h"
+#include "clc/internal/math/clc_sw_fma.h"
+#include "clc/math/clc_fma.h"
+#include "clc/math/math.h"
+
+#define __CLC_BODY "clc_fma.inc"
+#include "clc/math/gentype.inc"

libclc/clc/lib/spirv/math/clc_fma.inc

@@ -0,0 +1,16 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+_CLC_DEF _CLC_OVERLOAD __CLC_GENTYPE __clc_fma(__CLC_GENTYPE a, __CLC_GENTYPE b,
+                                               __CLC_GENTYPE c) {
+#if __CLC_FPSIZE == 32
+  if (!__clc_runtime_has_hw_fma32())
+    return __clc_sw_fma(a, b, c);
+#endif
+  return __builtin_elementwise_fma(a, b, c);
+}

libclc/clc/lib/spirv/math/clc_runtime_has_hw_fma32.cl

@@ -0,0 +1,13 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "clc/internal/math/clc_runtime_has_hw_fma32.h"
+
+bool __attribute__((noinline)) __clc_runtime_has_hw_fma32(void) {
+  return false;
+}

libclc/clc/lib/spirv/vulkan/CMakeLists.txt

@@ -1,4 +1,3 @@
 libclc_add_sources(${LIBCLC_CLC_TARGET} FILES
   integer/clc_mul_hi.cl
-  math/clc_sw_fma.cl
 )

libclc/opencl/lib/generic/math/fma.cl

@@ -7,7 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "clc/math/clc_fma.h"
-#include "clc/math/math.h"
 
 #define __CLC_FUNCTION fma
 #define __CLC_BODY "clc/shared/ternary_def.inc"

libclc/opencl/lib/spirv/CMakeLists.txt

@@ -4,6 +4,10 @@ if(LIBCLC_TARGET_OS AND EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBCLC_TARGET_OS})
 endif()
 
 # Non-Vulkan SPIR-V uses a curated subset of generic builtins.
+libclc_add_sources(${LIBCLC_OPENCL_TARGET} FILES
+  math/fma.cl
+)
+
 libclc_add_sources(${LIBCLC_OPENCL_TARGET}
   BASE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../generic
   FILES

libclc/opencl/lib/spirv/math/fma.cl

@@ -0,0 +1,15 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "clc/math/clc_fma.h"
+
+#define __CLC_FLOAT_ONLY
+#define __CLC_FUNCTION fma
+#define __CLC_BODY "clc/shared/ternary_def.inc"
+
+#include "clc/math/gentype.inc"