From 2484f7a4b0f52e6ed04754be336f1fa6fde47f6b Mon Sep 17 00:00:00 2001 From: Segher Boessenkool Date: Thu, 2 Sep 2021 16:38:24 +0000 Subject: [PATCH] rs6000: Don't use r12 for CR save on ELFv2 (PR102107) CR is saved and/or restored on some paths where GPR12 is already live since it has a meaning in the calling convention in the ELFv2 ABI. It is not completely clear to me that we can always use r11 here, but it does seem save, there is checking code (to detect conflicts here), and it is stage 1. So here goes. 2021-09-03 Segher Boessenkool PR target/102107 * config/rs6000/rs6000-logue.c (rs6000_emit_prologue): On ELFv2 use r11 instead of r12 for CR save, in all cases. --- gcc/config/rs6000/rs6000-logue.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/gcc/config/rs6000/rs6000-logue.c b/gcc/config/rs6000/rs6000-logue.c index 07337c4..e363d56 100644 --- a/gcc/config/rs6000/rs6000-logue.c +++ b/gcc/config/rs6000/rs6000-logue.c @@ -3293,10 +3293,13 @@ rs6000_emit_prologue (void) /* If we need to save CR, put it into r12 or r11. Choose r12 except when r12 will be needed by out-of-line gpr save. */ - cr_save_regno = ((DEFAULT_ABI == ABI_AIX || DEFAULT_ABI == ABI_ELFv2) - && !(strategy & (SAVE_INLINE_GPRS - | SAVE_NOINLINE_GPRS_SAVES_LR)) - ? 11 : 12); + if (DEFAULT_ABI == ABI_AIX + && !(strategy & (SAVE_INLINE_GPRS | SAVE_NOINLINE_GPRS_SAVES_LR))) + cr_save_regno = 11; + else if (DEFAULT_ABI == ABI_ELFv2) + cr_save_regno = 11; + else + cr_save_regno = 12; if (!WORLD_SAVE_P (info) && info->cr_save_p && REGNO (frame_reg_rtx) != cr_save_regno -- 2.7.4