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| author | Jeff Law <law@redhat.com> | 2005-01-31 20:48:52 -0700 |
|---|---|---|
| committer | Jeff Law <law@gcc.gnu.org> | 2005-01-31 20:48:52 -0700 |
| commit | dc5d4efbce3e6587b31da8d6d1c502aea80acfcc (patch) | |
| tree | 156482e0e2154f02927d2baaf5e214e13f2ba2d8 /gcc | |
| parent | 3dcec1e9e797af50ef38718cf19e0742e1c6a96a (diff) | |
| download | gcc-dc5d4efbce3e6587b31da8d6d1c502aea80acfcc.zip gcc-dc5d4efbce3e6587b31da8d6d1c502aea80acfcc.tar.gz gcc-dc5d4efbce3e6587b31da8d6d1c502aea80acfcc.tar.bz2 | |
fold-const.c (fold, [...]): Do not lose side effects when optimizing 0 % X.
* fold-const.c (fold, case CEIL_MOD_EXPR): Do not lose side
effects when optimizing 0 % X. Do not try to optimize X % 0.
* gcc.c-torture/execute/20050131-1.c: New test.
* gcc.dg/wcaselabel.c: New test.
From-SVN: r94516
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/fold-const.c | 13 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.c-torture/execute/20050131-1.c | 18 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/wcaselabel-1.c | 15 |
5 files changed, 54 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 1b5174e..5320b6d 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2005-01-31 Jeff Law <law@redhat.com> + + * fold-const.c (fold, case CEIL_MOD_EXPR): Do not lose side + effects when optimizing 0 % X. Do not try to optimize X % 0. + 2005-01-31 James E. Wilson <wilson@specifixinc.com> * config/ia64/itanium1.md (1_scall bypass): Change 2_mmalua to diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 13c57e0..2285742 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -7938,12 +7938,21 @@ fold (tree expr) case FLOOR_MOD_EXPR: case ROUND_MOD_EXPR: case TRUNC_MOD_EXPR: - /* 0 % X is always zero as is X % 1. */ - if (integer_zerop (arg0) || integer_onep (arg1)) + /* X % 1 is always zero, but be sure to preserve any side + effects in X. */ + if (integer_onep (arg1)) return omit_one_operand (type, integer_zero_node, arg0); + + /* X % 0, return X % 0 unchanged so that we can get the + proper warnings and errors. */ if (integer_zerop (arg1)) return t; + /* 0 % X is always zero, but be sure to preserve any side + effects in X. Place this after checking for X == 0. */ + if (integer_zerop (arg0)) + return omit_one_operand (type, integer_zero_node, arg1); + /* X % -1 is zero. */ if (!TYPE_UNSIGNED (type) && TREE_CODE (arg1) == INTEGER_CST diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 4c7011e..b697d41 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2005-01-31 Jeff Law <law@redhat.com> + + * gcc.c-torture/execute/20050131-1.c: New test. + * gcc.dg/wcaselabel.c: New test. + 2005-01-31 Mark Mitchell <mark@codesourcery.com> * g++.dg/other/warning1.C: Adjust error messags. diff --git a/gcc/testsuite/gcc.c-torture/execute/20050131-1.c b/gcc/testsuite/gcc.c-torture/execute/20050131-1.c new file mode 100644 index 0000000..9fae911 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/execute/20050131-1.c @@ -0,0 +1,18 @@ +/* Verify that we do not lose side effects on a MOD expression. */ + +#include <stdlib.h> +#include <stdio.h> + +int +foo (int a) +{ + int x = 0 % a++; + return a; +} + +main() +{ + if (foo (9) != 10) + abort (); + exit (0); +} diff --git a/gcc/testsuite/gcc.dg/wcaselabel-1.c b/gcc/testsuite/gcc.dg/wcaselabel-1.c new file mode 100644 index 0000000..6f673df --- /dev/null +++ b/gcc/testsuite/gcc.dg/wcaselabel-1.c @@ -0,0 +1,15 @@ +/* { dg-do compile } */ +/* { dg-options "-w" } */ + + +int foo(int x) +{ + switch(x) + { + + case 0 % 0: /* { dg-error "case label does not reduce to an integer constant" } */ + return 1; + default: + return 2; + } +} |