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| author | John Wehle <john@feith.com> | 2000-01-09 06:03:45 +0000 |
|---|---|---|
| committer | John Wehle <wehle@gcc.gnu.org> | 2000-01-09 06:03:45 +0000 |
| commit | cb0a34c469abd6fc7e6a54fe620706ff0f2f136f (patch) | |
| tree | 929408d70ce3a7b84c9acd4f8f43cf1758d6a7b5 /gcc/fold-const.c | |
| parent | d511f9d5ecc8d4f5a7a6dc1ba239ad67e0816773 (diff) | |
| download | gcc-cb0a34c469abd6fc7e6a54fe620706ff0f2f136f.zip gcc-cb0a34c469abd6fc7e6a54fe620706ff0f2f136f.tar.gz gcc-cb0a34c469abd6fc7e6a54fe620706ff0f2f136f.tar.bz2 | |
fold-const.c (lshift_double, [...]): Handle shifting by 2 * HOST_BITS_PER_WIDE_INT correctly.
* fold-const.c (lshift_double, rshift_double): Handle
shifting by 2 * HOST_BITS_PER_WIDE_INT correctly.
From-SVN: r31289
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 976cf3a..64d4e41 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -363,7 +363,14 @@ lshift_double (l1, h1, count, prec, lv, hv, arith) count %= prec; #endif - if (count >= HOST_BITS_PER_WIDE_INT) + if (count >= 2 * HOST_BITS_PER_WIDE_INT) + { + /* Shifting by the host word size is undefined according to the + ANSI standard, so we must handle this as a special case. */ + *hv = 0; + *lv = 0; + } + else if (count >= HOST_BITS_PER_WIDE_INT) { *hv = (unsigned HOST_WIDE_INT) l1 << (count - HOST_BITS_PER_WIDE_INT); *lv = 0; @@ -398,7 +405,14 @@ rshift_double (l1, h1, count, prec, lv, hv, arith) count %= prec; #endif - if (count >= HOST_BITS_PER_WIDE_INT) + if (count >= 2 * HOST_BITS_PER_WIDE_INT) + { + /* Shifting by the host word size is undefined according to the + ANSI standard, so we must handle this as a special case. */ + *hv = signmask; + *lv = signmask; + } + else if (count >= HOST_BITS_PER_WIDE_INT) { *hv = signmask; *lv = ((signmask << (2 * HOST_BITS_PER_WIDE_INT - count - 1) << 1) |