AArch64 has the same issue ARM had where the LR register was not used in
leaf functions. This was reported in
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42017. In AArch64, this
test-case need to be added with more live ranges for the need for the
LR_REGNUM. i.e test-case in the PR needs additional loops up to r31 for
the case AArch64 to see this.
The same fix (from the thread
https://gcc.gnu.org/ml/gcc-patches/2011-04/msg02191.html) which went
into ARM should apply to AArch64 as well. Regression tested on qemu for
aarch64-none-linux-gnu with no new regressions. Is this OK for trunk?
Thanks,
Kugan
gcc/ChangeLog:
2014-09-23 Kugan Vivekanandarajah <kug...@linaro.org>
* config/aarch64/aarch64.h (EPILOGUE_USES): Return true only after
epilogue_completed is true.
diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
index db950da..b3e4585 100644
--- a/gcc/config/aarch64/aarch64.h
+++ b/gcc/config/aarch64/aarch64.h
@@ -309,7 +309,7 @@ extern unsigned long aarch64_tune_flags;
considered live at the start of the called function. */
#define EPILOGUE_USES(REGNO) \
- ((REGNO) == LR_REGNUM)
+ (epilogue_completed && (REGNO) == LR_REGNUM)
/* EXIT_IGNORE_STACK should be nonzero if, when returning from a function,
the stack pointer does not matter. The value is tested only in
