glibc/glibc-rh1783303-14.patch

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commit e68b1151f7460d5fa88c3a567c13f66052da79a7
Author: Paul A. Clarke <pc@us.ibm.com>
Date: Thu Sep 19 11:39:44 2019 -0500
[powerpc] __fesetround_inline optimizations
On POWER9, use more efficient means to update the 2-bit rounding mode
via the 'mffscrn' instruction (instead of two 'mtfsb0/1' instructions
or one 'mtfsfi' instruction that modifies 4 bits).
Suggested-by: Paul E. Murphy <murphyp@linux.ibm.com>
Reviewed-By: Paul E Murphy <murphyp@linux.ibm.com>
diff --git a/sysdeps/powerpc/fpu/fenv_libc.h b/sysdeps/powerpc/fpu/fenv_libc.h
index 86ae7fda016abd8b..c3f541c08440b20e 100644
--- a/sysdeps/powerpc/fpu/fenv_libc.h
+++ b/sysdeps/powerpc/fpu/fenv_libc.h
@@ -149,7 +149,12 @@ typedef union
static inline int
__fesetround_inline (int round)
{
- if ((unsigned int) round < 2)
+#ifdef _ARCH_PWR9
+ __fe_mffscrn (round);
+#else
+ if (__glibc_likely (GLRO(dl_hwcap2) & PPC_FEATURE2_ARCH_3_00))
+ __fe_mffscrn (round);
+ else if ((unsigned int) round < 2)
{
asm volatile ("mtfsb0 30");
if ((unsigned int) round == 0)
@@ -165,7 +170,7 @@ __fesetround_inline (int round)
else
asm volatile ("mtfsb1 31");
}
-
+#endif
return 0;
}
@@ -174,7 +179,14 @@ __fesetround_inline (int round)
static inline void
__fesetround_inline_nocheck (const int round)
{
- asm volatile ("mtfsfi 7,%0" : : "i" (round));
+#ifdef _ARCH_PWR9
+ __fe_mffscrn (round);
+#else
+ if (__glibc_likely (GLRO(dl_hwcap2) & PPC_FEATURE2_ARCH_3_00))
+ __fe_mffscrn (round);
+ else
+ asm volatile ("mtfsfi 7,%0" : : "i" (round));
+#endif
}
#define FPSCR_MASK(bit) (1 << (31 - (bit)))