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

[Thomas Preudhomme]

My bad, I used dg-cmp-results without verbosity which didn't show the
problem It starts to show it with -v -v, I'm not sure why. I'll have a
look right now and revert by the end of today if I cannot come up with
a fix. Does that sound ok?

Best regards,

Thomas
On Thu, 4 Oct 2018 at 12:31, H.J. Lu <hjl.tools@gmail.com> wrote:
>
> 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.