Re: optimization/7476: constant variable tested in loop

[Andrew Pinski <pinskia@physics.uc.edu>]

The following reply was made to PR optimization/7476; it has been noted by GNATS.

From: Andrew Pinski <pinskia@physics.uc.edu>
To: Kevin Ryde <user42@zip.com.au>
Cc: gcc-gnats@gcc.gnu.org
Subject: Re: optimization/7476: constant variable tested in loop
Date: Fri, 2 Aug 2002 19:12:02 -0400

 This has been fixed in at least gcc 3.3 20020802 (experimental):
          .file   "foo.c"
          .text
          .align 2
          .p2align 4,,15
 .globl foo
          .type   foo, @function
 foo:
          pushl   %ebp
          movl    $9, %eax
          movl    %esp, %ebp
          .p2align 4,,15
 .L7:
          decl    %eax
          jns     .L7
          popl    %ebp
          ret
          .size   foo, .-foo
          .ident  "GCC: (GNU) 3.3 20020802 (experimental)"
 
 which is compared to gcc 3.1.1:
          .file   "foo.c"
          .section        .rodata.str1.1,"aMS",@progbits,1
 .LC0:
          .string "hello"
          .text
          .align 2
          .p2align 4,,15
 .globl foo
          .type   foo,@function
 foo:
          pushl   %ebp
          movl    %esp, %ebp
          pushl   %esi
          xorl    %esi, %esi
          pushl   %ebx
          movl    $9, %ebx
          subl    $16, %esp
          .p2align 4,,15
 .L7:
          testl   %esi, %esi
          jne     .L10
 .L4:
          decl    %ebx
          jns     .L7
          addl    $16, %esp
          popl    %ebx
          popl    %esi
          popl    %ebp
          ret
          .p2align 4,,7
 .L10:
          movl    $.LC0, (%esp)
          call    puts
          jmp     .L4
 .Lfe1:
          .size   foo,.Lfe1-foo
          .ident  "GCC: (GNU) 3.1.1"