[PATCH] ARC:fpu: add extra capability check before use of sqrt and fma builtins

[Pavel.Kozlov at synopsys.com]

From: Pavel Kozlov <pavel.kozlov at synopsys.com>

Add extra check for compiler definitions to ensure that compiler provides
sqrt and fma hw fpu instructions else use software implementation.

As divide/sqrt and FMA hw support from CPU side is optional,
the compiler can be configured by options to generate hw FPU instructions,
but without use of FDDIV, FDSQRT, FSDIV, FSSQRT, FDMADD and FSMADD
instructions. In this case __builtin_sqrt and __builtin_sqrtf provided by
compiler can't be used inside the glibc code, as these builtins are used
in implementations of sqrt() and sqrtf() functions but at the same time
these builtins unfold to sqrt() and sqrtf(). So it is possible to receive
code like that:

0001c4b4 <__ieee754_sqrtf>:
   1c4b4:    0001 0000      b     0         ;1c4b4 <__ieee754_sqrtf>

The same is also true for __builtin_fma and __builtin_fmaf.
---
 sysdeps/arc/fpu/math-use-builtins-fma.h  | 14 ++++++++++++--
 sysdeps/arc/fpu/math-use-builtins-sqrt.h | 14 ++++++++++++--
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/sysdeps/arc/fpu/math-use-builtins-fma.h b/sysdeps/arc/fpu/math-use-builtins-fma.h
index eede75aa41be..082badf48201 100644
--- a/sysdeps/arc/fpu/math-use-builtins-fma.h
+++ b/sysdeps/arc/fpu/math-use-builtins-fma.h
@@ -1,4 +1,14 @@
-#define USE_FMA_BUILTIN 1
-#define USE_FMAF_BUILTIN 1
+#if defined __ARC_FPU_DP_DIV__
+# define USE_SQRT_BUILTIN 1
+#else
+# define USE_SQRT_BUILTIN 0
+#endif
+
+#if defined __ARC_FPU_SP_DIV__
+# define USE_SQRTF_BUILTIN 1
+#else
+# define USE_SQRTF_BUILTIN 0
+#endif
+
 #define USE_FMAL_BUILTIN 0
 #define USE_FMAF128_BUILTIN 0
diff --git a/sysdeps/arc/fpu/math-use-builtins-sqrt.h b/sysdeps/arc/fpu/math-use-builtins-sqrt.h
index e94c915ba66a..a449bc609295 100644
--- a/sysdeps/arc/fpu/math-use-builtins-sqrt.h
+++ b/sysdeps/arc/fpu/math-use-builtins-sqrt.h
@@ -1,4 +1,14 @@
-#define USE_SQRT_BUILTIN 1
-#define USE_SQRTF_BUILTIN 1
+#if defined __ARC_FPU_DP_DIV__
+# define USE_SQRT_BUILTIN 1
+#else
+# define USE_SQRT_BUILTIN 0
+#endif
+
+#if defined __ARC_FPU_SP_DIV__
+# define USE_SQRTF_BUILTIN 1
+#else
+# define USE_SQRTF_BUILTIN 0
+#endif
+
 #define USE_SQRTL_BUILTIN 0
 #define USE_SQRTF128_BUILTIN 0
-- 
2.25.1