65 lines
2.4 KiB
Diff
65 lines
2.4 KiB
Diff
commit 7b8481b330720d28c019a2e5994492a1923d5daa
|
|
Author: Paul A. Clarke <pc@us.ibm.com>
|
|
Date: Thu Sep 19 11:11:04 2019 -0500
|
|
|
|
[powerpc] No need to enter "Ignore Exceptions Mode"
|
|
|
|
Since at least POWER8, there is no performance advantage to entering
|
|
"Ignore Exceptions Mode", and doing so conditionally requires
|
|
- the conditional logic, and
|
|
- a system call.
|
|
|
|
Make it a no-op for uses within glibc.
|
|
|
|
diff --git a/sysdeps/powerpc/fpu/fenv_private.h b/sysdeps/powerpc/fpu/fenv_private.h
|
|
index 666fbfdd9fef7759..e09137e892a8e3f3 100644
|
|
--- a/sysdeps/powerpc/fpu/fenv_private.h
|
|
+++ b/sysdeps/powerpc/fpu/fenv_private.h
|
|
@@ -23,6 +23,17 @@
|
|
#include <fenv_libc.h>
|
|
#include <fpu_control.h>
|
|
|
|
+#ifdef _ARCH_PWR8
|
|
+/* There is no performance advantage to non-stop mode. */
|
|
+/* The odd syntax here is to innocuously reference the given variables
|
|
+ to prevent warnings about unused variables. */
|
|
+#define __TEST_AND_BEGIN_NON_STOP(old, new) do {} while ((old) * (new) * 0 != 0)
|
|
+#define __TEST_AND_END_NON_STOP(old, new) do {} while ((old) * (new) * 0 != 0)
|
|
+#else
|
|
+#define __TEST_AND_BEGIN_NON_STOP __TEST_AND_ENTER_NON_STOP
|
|
+#define __TEST_AND_END_NON_STOP __TEST_AND_EXIT_NON_STOP
|
|
+#endif
|
|
+
|
|
static __always_inline void
|
|
libc_feholdexcept_setround_ppc (fenv_t *envp, int r)
|
|
{
|
|
@@ -30,7 +41,7 @@ libc_feholdexcept_setround_ppc (fenv_t *envp, int r)
|
|
|
|
old.fenv = *envp = fegetenv_register ();
|
|
|
|
- __TEST_AND_ENTER_NON_STOP (old.l, 0ULL);
|
|
+ __TEST_AND_BEGIN_NON_STOP (old.l, 0ULL);
|
|
|
|
/* Clear everything and set the rounding mode. */
|
|
new.l = r;
|
|
@@ -49,8 +60,8 @@ __libc_femergeenv_ppc (const fenv_t *envp, unsigned long long old_mask,
|
|
/* Merge bits while masking unwanted bits from new and old env. */
|
|
new.l = (old.l & old_mask) | (new.l & new_mask);
|
|
|
|
- __TEST_AND_EXIT_NON_STOP (old.l, new.l);
|
|
- __TEST_AND_ENTER_NON_STOP (old.l, new.l);
|
|
+ __TEST_AND_END_NON_STOP (old.l, new.l);
|
|
+ __TEST_AND_BEGIN_NON_STOP (old.l, new.l);
|
|
|
|
/* If requesting to keep status, replace control, and merge exceptions,
|
|
and exceptions haven't changed, we can just set new control instead
|
|
@@ -141,7 +152,7 @@ libc_feholdsetround_noex_ppc_ctx (struct rm_ctx *ctx, int r)
|
|
ctx->env = old.fenv;
|
|
if (__glibc_unlikely (new.l != old.l))
|
|
{
|
|
- __TEST_AND_ENTER_NON_STOP (old.l, 0ULL);
|
|
+ __TEST_AND_BEGIN_NON_STOP (old.l, 0ULL);
|
|
fesetenv_control (new.fenv);
|
|
ctx->updated_status = true;
|
|
}
|