[Bug target/70763] New: Use SSE for DImode load/store

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70763

            Bug ID: 70763
           Summary: Use SSE for DImode load/store
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hjl.tools at gmail dot com
                CC: ienkovich at gcc dot gnu.org
  Target Milestone: ---
            Target: i386

On i386, we should use SSE for DImode load/store:

[hjl@gnu-6 pr70155d]$ cat x1.i
extern long long a, b;

void
foo (void)
{
  a = b;
}
[hjl@gnu-6 pr70155d]$ cat x2.i
struct foo
{
  long long i;
}__attribute__ ((packed));

extern struct foo x, y;

void
foo (void)
{
  x = y;
}
[hjl@gnu-6 pr70155d]$ cat x5.i
extern long long a;

void
foo (void)
{
  a = 0;
}
[hjl@gnu-6 pr70155d]$ cat x6.i
extern long long a;

void
foo (void)
{
  a = -1;
}
[hjl@gnu-6 pr70155d]$ make x1.s x2.s x5.s x6.s
/export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -O2 -msse2 -m32
-fno-asynchronous-unwind-tables -S -o x1.s x1.i
/export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -O2 -msse2 -m32
-fno-asynchronous-unwind-tables -S -o x2.s x2.i
/export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -O2 -msse2 -m32
-fno-asynchronous-unwind-tables -S -o x5.s x5.i
/export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -O2 -msse2 -m32
-fno-asynchronous-unwind-tables -S -o x6.s x6.i
[hjl@gnu-6 pr70155d]$ cat  x1.s x2.s x5.s x6.s
        .file   "x1.i"
        .text
        .p2align 4,,15
        .globl  foo
        .type   foo, @function
foo:
        movl    b, %eax
        movl    b+4, %edx
        movl    %eax, a
        movl    %edx, a+4
        ret
        .size   foo, .-foo
        .ident  "GCC: (GNU) 7.0.0 20160422 (experimental)"
        .section        .note.GNU-stack,"",@progbits
        .file   "x2.i"
        .text
        .p2align 4,,15
        .globl  foo
        .type   foo, @function
foo:
        movl    y, %eax
        movl    y+4, %edx
        movl    %eax, x
        movl    %edx, x+4
        ret
        .size   foo, .-foo
        .ident  "GCC: (GNU) 7.0.0 20160422 (experimental)"
        .section        .note.GNU-stack,"",@progbits
        .file   "x5.i"
        .text
        .p2align 4,,15
        .globl  foo
        .type   foo, @function
foo:
        movl    $0, a
        movl    $0, a+4
        ret
        .size   foo, .-foo
        .ident  "GCC: (GNU) 7.0.0 20160422 (experimental)"
        .section        .note.GNU-stack,"",@progbits
        .file   "x6.i"
        .text
        .p2align 4,,15
        .globl  foo
        .type   foo, @function
foo:
        movl    $-1, a
        movl    $-1, a+4
        ret
        .size   foo, .-foo
        .ident  "GCC: (GNU) 7.0.0 20160422 (experimental)"
        .section        .note.GNU-stack,"",@progbits
[hjl@gnu-6 pr70155d]$ 

They all can use SSE loa/store.