On Tue, Sep 27, 2016 at 09:55:24AM +0200, Eric Botcazou wrote:
> > Seconded. The warning should take into account existing practices instead
> > of forcing the user to make completely bogus changes to the code (and Ada
> > should have been tested before the patch was approved).
>
> I have a bootstrap failure on x86-64/Linux:
>
> /home/eric/svn/gcc/gcc/combine.c: In function 'rtx_code
> simplify_comparison(rtx_code, rtx_def**, rtx_def**)':
> /home/eric/svn/gcc/gcc/combine.c:11928:11: error: this statement may fall
> through [-Werror=implicit-fallthrough]
> break;
> ^
> /home/eric/svn/gcc/gcc/combine.c:11932:2: note: here
> case ZERO_EXTEND:
> ^~~~
> /home/eric/svn/gcc/gcc/combine.c:12340:6: error: this statement may fall
> through [-Werror=implicit-fallthrough]
> }
> ^
> /home/eric/svn/gcc/gcc/combine.c:12343:2: note: here
> case LSHIFTRT:
> ^~~~
>
> /* ... fall through ... */
>
> /* ... fall through ... */
>
Yeah, I ran into this and another issue in i386.c. Fixed thusly,
bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2016-09-26 Jakub Jelinek <ja...@redhat.com>
* combine.c (simplify_comparison): Add canonical FALLTHROUGH comments.
* config/i386/i386.c (ix86_dep_by_shift_count_body): Add FALLTHROUGH
comments. Remove break after return.
(ix86_fp_compare_code_to_integer, has_dispatch,
ix86_simd_clone_usable): Remove break after return.
--- gcc/combine.c.jj 2016-09-19 16:33:57.000000000 +0200
+++ gcc/combine.c 2016-09-26 22:15:39.553198973 +0200
@@ -11923,11 +11923,11 @@ simplify_comparison (enum rtx_code code,
we can treat the SUBREG as if it were a ZERO_EXTEND. */
if (subreg_lowpart_p (op0)
&& GET_MODE_PRECISION (GET_MODE (SUBREG_REG (op0))) < mode_width)
- /* Fall through */ ;
+ ;
else
break;
- /* ... fall through ... */
+ /* FALLTHROUGH */
case ZERO_EXTEND:
mode = GET_MODE (XEXP (op0, 0));
@@ -12339,7 +12339,7 @@ simplify_comparison (enum rtx_code code,
continue;
}
- /* ... fall through ... */
+ /* FALLTHROUGH */
case LSHIFTRT:
/* If we have (compare (xshiftrt FOO N) (const_int C)) and
the low order N bits of FOO are known to be zero, we can do this
--- gcc/config/i386/i386.c.jj 2016-09-26 20:22:23.000000000 +0200
+++ gcc/config/i386/i386.c 2016-09-26 23:15:46.988142242 +0200
@@ -21237,9 +21237,9 @@ ix86_dep_by_shift_count_body (const_rtx
if (ix86_dep_by_shift_count_body (XVECEXP (set_body, 0, i),
use_body))
return true;
+ /* FALLTHROUGH */
default:
return false;
- break;
}
/* Retrieve shift count of USE_BODY. */
@@ -21253,9 +21253,9 @@ ix86_dep_by_shift_count_body (const_rtx
if (ix86_dep_by_shift_count_body (set_body,
XVECEXP (use_body, 0, i)))
return true;
+ /* FALLTHROUGH */
default:
return false;
- break;
}
if (shift_rtx
@@ -22369,19 +22369,14 @@ ix86_fp_compare_code_to_integer (enum rt
case ORDERED:
case UNORDERED:
return code;
- break;
case UNEQ:
return EQ;
- break;
case UNLT:
return LTU;
- break;
case UNLE:
return LEU;
- break;
case LTGT:
return NE;
- break;
default:
return UNKNOWN;
}
@@ -49500,7 +49495,6 @@ has_dispatch (rtx_insn *insn, int action
case IS_DISPATCH_ON:
return true;
- break;
case IS_CMP:
return is_cmp (insn);
@@ -49958,7 +49952,6 @@ ix86_simd_clone_usable (struct cgraph_no
if (!TARGET_AVX)
return -1;
return TARGET_AVX2 ? 1 : 0;
- break;
case 'd':
if (!TARGET_AVX2)
return -1;
Jakub
