Re: [PATCH, LRA] Never reload fixed form constraints memory operand

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Wed, Oct 3, 2018 at 8:12 PM Vladimir Makarov <vmakarov@redhat.com> wrote:
>
> On 10/03/2018 12:47 PM, Thomas Preudhomme wrote:
> > Best regards,
> >
> > Thomas
> >
> > never_reload_fixed_address_operand.patch
> >
> >
> >  From 2831d8b886d92513c2d30d43a6a989d2bbd0ceee Mon Sep 17 00:00:00 2001
> > From: Thomas Preud'homme<thomas.preudhomme@linaro.org>
> > Date: Thu, 27 Sep 2018 09:50:12 +0100
> > Subject: [PATCH] [PATCH, LRA] Never reload fixed form constraints memory
> >   operand
> >
> > Hi,
> >
> > The unconditional reload of address operand for recognized instruction
> > in process_address_1 prevent the patch for fixing "PR85434: Address of
> > stack protector guard spilled to stack on ARM" proposed at [1]. The code
> > in this patch attempt to control which registers are used to make PIC
> > access but the reload performed by process_address_1 will use generic
> > PIC access. This patch removes the test for the instruction to be
> > unrecognized to do the reload, thus always avoiding to reload address
> > operand for fixed constraints (such as "X" used in the patch).
> >
> > [1]https://gcc.gnu.org/ml/gcc-patches/2018-08/msg01838.html
> >
> > ChangeLog entry is as follows:
> >
> > *** gcc/ChangeLog ***
> >
> > 2018-10-03  Thomas Preud'homme<thomas.preudhomme@linaro.org>
> >
> >       * lra-constraints.c (process_address_1): Bail out for all
> >       satisfied fixed constraints.
> >
> > Testing: Successfully bootstrapped and regtested on:
> > - arm-linux-gnueabihf (both Arm and Thumb2 mode)
> > - aarch64-linux-gnu
> > - x86_64-linux-gnu
> > - i386-linux-gnu
> > - sparc64-linux-gnu (gcc202)
> > - powerpc64le-linux-gnu (gcc112)
> >
> > Is this ok for trunk?
> >
> OK. Thank you for testing all these targets, Thomas.
>

This caused:

FAIL: gcc.target/i386/pr83317.c (internal compiler error)
FAIL: gcc.target/i386/pr83317.c (test for excess errors)

[hjl@gnu-4 gcc]$
/export/build/gnu/tools-build/gcc-debug/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/tools-build/gcc-debug/build-x86_64-linux/gcc/
/export/gnu/import/git/sources/gcc/gcc/testsuite/gcc.target/i386/pr83317.c
 -m32   -fno-diagnostics-show-caret -fno-diagnostics-show-line-numbers
-fdiagnostics-color=never   -O1 -fPIC -msse2 -mfpmath=sse -S -o
pr83317.s
during RTL pass: reload
/export/gnu/import/git/sources/gcc/gcc/testsuite/gcc.target/i386/pr83317.c:
In function \u2018foo\u2019:
/export/gnu/import/git/sources/gcc/gcc/testsuite/gcc.target/i386/pr83317.c:21:1:
internal compiler error: in lra_eliminate_reg_if_possible, at
lra-eliminations.c:1393
0xea4875 lra_eliminate_reg_if_possible(rtx_def**)
/export/gnu/import/git/sources/gcc/gcc/lra-eliminations.c:1393
0xe8a94c address_eliminator
/export/gnu/import/git/sources/gcc/gcc/lra-constraints.c:362
0xe8aaf7 satisfies_memory_constraint_p
/export/gnu/import/git/sources/gcc/gcc/lra-constraints.c:401
0xe8f947 process_alt_operands
/export/gnu/import/git/sources/gcc/gcc/lra-constraints.c:2248
0xe93d1f curr_insn_transform
/export/gnu/import/git/sources/gcc/gcc/lra-constraints.c:3861
0xe975f2 lra_constraints(bool)
/export/gnu/import/git/sources/gcc/gcc/lra-constraints.c:4878
0xe7c458 lra(_IO_FILE*)
/export/gnu/import/git/sources/gcc/gcc/lra.c:2446
0xe111ff do_reload
/export/gnu/import/git/sources/gcc/gcc/ira.c:5469
0xe116f2 execute
/export/gnu/import/git/sources/gcc/gcc/ira.c:5653
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
[hjl@gnu-4 gcc]$


-- 
H.J.