We don't need a register that can live across the syscall;
we only need a register that can live until the syscall.
Use call-clobbered r11 instead of call-saved r14.
Eliminate the save and restore of r14 from the stack frame.
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
linux-user/host/ppc64/safe-syscall.inc.S | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/linux-user/host/ppc64/safe-syscall.inc.S
b/linux-user/host/ppc64/safe-syscall.inc.S
index 4b57440585..5f19cd193c 100644
--- a/linux-user/host/ppc64/safe-syscall.inc.S
+++ b/linux-user/host/ppc64/safe-syscall.inc.S
@@ -49,9 +49,7 @@ safe_syscall_base:
* and returns the result in r3
* Shuffle everything around appropriately.
*/
- std 14, 16(1) /* Preserve r14 in SP+16 */
- .cfi_offset 14, 16
- mr 14, 3 /* signal_pending */
+ mr 11, 3 /* signal_pending */
mr 0, 4 /* syscall number */
mr 3, 5 /* syscall arguments */
mr 4, 6
@@ -69,13 +67,12 @@ safe_syscall_base:
*/
safe_syscall_start:
/* if signal_pending is non-zero, don't do the call */
- lwz 12, 0(14)
+ lwz 12, 0(11)
cmpwi 0, 12, 0
bne- 0f
sc
safe_syscall_end:
/* code path when we did execute the syscall */
- ld 14, 16(1) /* restore r14 to its original value */
bnslr+
/* syscall failed; return negative errno */
@@ -84,7 +81,6 @@ safe_syscall_end:
/* code path when we didn't execute the syscall */
0: addi 3, 0, -TARGET_ERESTARTSYS
- ld 14, 16(1) /* restore r14 to its original value */
blr
.cfi_endproc
--
2.25.1
