[Bug target/101922] New: mips: illegal instruction at -O3 with -mmsa -mloongson-mmi

[Bug target/101922] New: mips: illegal instruction at -O3 with -mmsa -mloongson-mmi

[xry111 at mengyan1223 dot wang]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101922

            Bug ID: 101922
           Summary: mips: illegal instruction at -O3 with -mmsa
                    -mloongson-mmi
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: xry111 at mengyan1223 dot wang
  Target Milestone: ---

$ cat test.c
int x = 0xffffffff;
char d[16];

void f() {
  int i;
  for (i = 0; i < 16; i++) {
    int t = d[i] >> 8;
    x &= t;
  }
}
$ ~/git-repos/gcc-test-mips/gcc/cc1 test.c -O3 -mmsa -mloongson-mmi -nostdinc
$ mips64el-unknown-linux-gnu-as test.s -mmsa -mloongson-mmi -mips64r2
test.s: Assembler messages:
test.s:29: Error: operand 3 out of range `srai.b $w0,$w0,8'

[Bug target/101922] mips: illegal instruction at -O3 with -mmsa -mloongson-mmi

[xry111 at mengyan1223 dot wang]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101922

--- Comment #1 from Xi Ruoyao <xry111 at mengyan1223 dot wang> ---
Technically the testcase above invokes UB, but this is reduced from a file in
openssl-1.1.1k.

[Bug target/101922] mips: illegal instruction at -O3 with -mmsa -mloongson-mmi

[xry111 at mengyan1223 dot wang]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101922

--- Comment #2 from Xi Ruoyao <xry111 at mengyan1223 dot wang> ---
A "legal" testcase w/o UB (and may have some usage in practice):

typedef __INT8_TYPE__ i8;
typedef __INT32_TYPE__ i32;

i8 d[16];

i32 f(i32 x) {
  int i;
  for (i = 0; i < 16; i++) {
    __INT32_TYPE__ t = (__INT32_TYPE__) d[i] >> 31;
    x &= t;
  }
  return x;
}

[Bug target/101922] mips: illegal instruction at -O3 with -mmsa -mloongson-mmi

[xry111 at mengyan1223 dot wang]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101922

Xi Ruoyao <xry111 at mengyan1223 dot wang> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |patch

--- Comment #3 from Xi Ruoyao <xry111 at mengyan1223 dot wang> ---
Patch: https://gcc.gnu.org/pipermail/gcc-patches/2021-August/577849.html

[Bug target/101922] mips: illegal instruction at -O3 with -mmsa -mloongson-mmi

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101922

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Xi Ruoyao <xry111@gcc.gnu.org>:

https://gcc.gnu.org/g:f93f0868919ab32bfbc24adb40158298031a4d58

commit r12-3063-gf93f0868919ab32bfbc24adb40158298031a4d58
Author: Xi Ruoyao <xry111@mengyan1223.wang>
Date:   Fri Aug 20 22:52:57 2021 +0800

    mips: msa: truncate immediate shift amount [PR101922]

    When -mloongson-mmi is enabled, SHIFT_COUNT_TRUNCATED is turned off.
    This causes untruncated immediate shift amount outputed into the asm,
    and the GNU assembler refuses to assemble it.

    Truncate immediate shift amount when outputing the asm instruction to
    make GAS happy again.

    gcc/

            PR target/101922
            * config/mips/mips-protos.h (mips_msa_output_shift_immediate):
              Declare.
            * config/mips/mips.c (mips_msa_output_shift_immediate): New
              function.
            * config/mips/mips-msa.md (vashl<mode>3, vashr<mode>3,
              vlshr<mode>3): Call it.

    gcc/testsuite/

            PR target/101922
            * gcc.target/mips/pr101922.c: New test.

[Bug target/101922] mips: illegal instruction at -O3 with -mmsa -mloongson-mmi

[xry111 at mengyan1223 dot wang]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101922

Xi Ruoyao <xry111 at mengyan1223 dot wang> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |FIXED

--- Comment #5 from Xi Ruoyao <xry111 at mengyan1223 dot wang> ---
Fixed in trunk.

[Bug target/101922] mips: illegal instruction at -O3 with -mmsa -mloongson-mmi

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101922

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |12.0