From 50025f916d5c996973bcc0af1b020f1857c4e7ed Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Wed, 14 Sep 2011 14:32:07 +0000 Subject: [PATCH] re PR middle-end/50251 (Revision 178353 caused many test failures) 2011-09-14 Tom de Vries PR middle-end/50251 * explow.c (emit_stack_restore): Set crtl->need_drap if stack_restore is emitted. From-SVN: r178853 --- gcc/ChangeLog | 6 ++++++ gcc/explow.c | 14 ++++++++++++++ 2 files changed, 20 insertions(+) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 1770b738dfc5..384245996248 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2011-09-14 Tom de Vries + + PR middle-end/50251 + * explow.c (emit_stack_restore): Set crtl->need_drap if + stack_restore is emitted. + 2011-09-14 Julian Brown * config/arm/arm.c (arm_override_options): Add unaligned_access diff --git a/gcc/explow.c b/gcc/explow.c index 984150efd05a..11dffedd4b0f 100644 --- a/gcc/explow.c +++ b/gcc/explow.c @@ -1062,6 +1062,20 @@ emit_stack_restore (enum save_level save_level, rtx sa) /* The default is that we use a move insn. */ rtx (*fcn) (rtx, rtx) = gen_move_insn; + /* If stack_realign_drap, the x86 backend emits a prologue that aligns both + STACK_POINTER and HARD_FRAME_POINTER. + If stack_realign_fp, the x86 backend emits a prologue that aligns only + STACK_POINTER. This renders the HARD_FRAME_POINTER unusable for accessing + aligned variables, which is reflected in ix86_can_eliminate. + We normally still have the realigned STACK_POINTER that we can use. + But if there is a stack restore still present at reload, it can trigger + mark_not_eliminable for the STACK_POINTER, leaving no way to eliminate + FRAME_POINTER into a hard reg. + To prevent this situation, we force need_drap if we emit a stack + restore. */ + if (SUPPORTS_STACK_ALIGNMENT) + crtl->need_drap = true; + /* See if this machine has anything special to do for this kind of save. */ switch (save_level) { -- 2.47.2