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[PATCH] Fix up bootstrap on i686 --with-arch=corei7 --with-fpmath=sse (PR bootstrap/69677)
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Uros Bizjak <ubizjak at gmail dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Fri, 5 Feb 2016 00:04:44 +0100
- Subject: [PATCH] Fix up bootstrap on i686 --with-arch=corei7 --with-fpmath=sse (PR bootstrap/69677)
- Authentication-results: sourceware.org; auth=none
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
As mentioned in the PR, the convert_scalars_to_vector hunk is important,
without that we e.g. miscompile simplify-rtx.c.
The following patch restores that hunk and extends disabling of TARGET_STV
also for the 64-bit, but not 128-bit, aligned preferred or incoming stack
boundaries (also non-default).
Bootstrapped/regtested on i686-linux --with-arch=corei7 --with-tune=corei7
--with-fpmath=sse.
Alternatively, it is enough to just adjust stack_alignment_estimated in
there and keep stack_alignment_needed as is, that version has also been
successfully bootstrapped on i686-linux --with-arch=corei7
--with-tune=corei7 --with-fpmath=sse.
2016-02-04 Jakub Jelinek <jakub@redhat.com>
PR bootstrap/69677
* config/i386/i386.c (convert_scalars_to_vector): Readd stack
alignment fixes.
(ix86_option_override_internal): Disable TARGET_STV even for
-m{incoming,preferred}-stack-boundary=3.
--- gcc/config/i386/i386.c.jj 2016-02-04 18:59:38.309204574 +0100
+++ gcc/config/i386/i386.c 2016-02-04 21:54:02.439904261 +0100
@@ -3588,6 +3588,16 @@ convert_scalars_to_vector ()
bitmap_obstack_release (NULL);
df_process_deferred_rescans ();
+ /* Conversion means we may have 128bit register spills/fills
+ which require aligned stack. */
+ if (converted_insns)
+ {
+ if (crtl->stack_alignment_needed < 128)
+ crtl->stack_alignment_needed = 128;
+ if (crtl->stack_alignment_estimated < 128)
+ crtl->stack_alignment_estimated = 128;
+ }
+
return 0;
}
@@ -5443,12 +5453,12 @@ ix86_option_override_internal (bool main
opts->x_target_flags |= MASK_VZEROUPPER;
if (!(opts_set->x_target_flags & MASK_STV))
opts->x_target_flags |= MASK_STV;
- /* Disable STV if -mpreferred-stack-boundary=2 or
- -mincoming-stack-boundary=2 - the needed
+ /* Disable STV if -mpreferred-stack-boundary={2,3} or
+ -mincoming-stack-boundary={2,3} - the needed
stack realignment will be extra cost the pass doesn't take into
account and the pass can't realign the stack. */
- if (ix86_preferred_stack_boundary < 64
- || ix86_incoming_stack_boundary < 64)
+ if (ix86_preferred_stack_boundary < 128
+ || ix86_incoming_stack_boundary < 128)
opts->x_target_flags &= ~MASK_STV;
if (!ix86_tune_features[X86_TUNE_AVX256_UNALIGNED_LOAD_OPTIMAL]
&& !(opts_set->x_target_flags & MASK_AVX256_SPLIT_UNALIGNED_LOAD))
Jakub