The code was passing a pseudo rather than its allocated hard reg
to ira_need_caller_save_p. Running under valgrind to reproduce
the failure also showed that ALLOCNO_CROSSED_CALLS_ABIS wasn't
being explicitly initialised.
Tested on aarch64-linux-gnu and cross-tested against the testcase
on cris-elf. Applied as obvious.
Richard
2019-10-01 Richard Sandiford <richard.sandif...@arm.com>
gcc/
PR rtl-optimization/91948
* ira-build.c (ira_create_allocno): Initialize
ALLOCNO_CROSSED_CALLS_ABIS.
* ira-color.c (allocno_reload_assign): Pass hard_regno rather
than regno to ira_need_caller_save_p.
Index: gcc/ira-build.c
===================================================================
--- gcc/ira-build.c 2019-10-01 09:55:35.134088716 +0100
+++ gcc/ira-build.c 2019-10-01 13:55:02.074324628 +0100
@@ -504,6 +504,7 @@ ira_create_allocno (int regno, bool cap_
ALLOCNO_CALL_FREQ (a) = 0;
ALLOCNO_CALLS_CROSSED_NUM (a) = 0;
ALLOCNO_CHEAP_CALLS_CROSSED_NUM (a) = 0;
+ ALLOCNO_CROSSED_CALLS_ABIS (a) = 0;
CLEAR_HARD_REG_SET (ALLOCNO_CROSSED_CALLS_CLOBBERED_REGS (a));
#ifdef STACK_REGS
ALLOCNO_NO_STACK_REG_P (a) = false;
Index: gcc/ira-color.c
===================================================================
--- gcc/ira-color.c 2019-09-30 17:20:49.594663967 +0100
+++ gcc/ira-color.c 2019-10-01 13:55:02.074324628 +0100
@@ -4398,7 +4398,7 @@ allocno_reload_assign (ira_allocno_t a,
? ALLOCNO_CLASS_COST (a)
: ALLOCNO_HARD_REG_COSTS (a)[ira_class_hard_reg_index
[aclass][hard_regno]]));
- if (ira_need_caller_save_p (a, regno))
+ if (ira_need_caller_save_p (a, hard_regno))
{
ira_assert (flag_caller_saves);
caller_save_needed = 1;
