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| author | Jakub Jelinek <jakub@redhat.com> | 2012-12-12 10:38:56 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2012-12-12 10:38:56 +0100 |
| commit | ee3ae4f768dca3e67388018ee438c420eff43885 (patch) | |
| tree | 4987c888aa436f9bb7c2a6b24dc960bd3d0a5118 /libgcc/fixed-bit.c | |
| parent | 4c052539b6f9b5c5332d01e7dbc2c04e2477db85 (diff) | |
| download | gcc-ee3ae4f768dca3e67388018ee438c420eff43885.zip gcc-ee3ae4f768dca3e67388018ee438c420eff43885.tar.gz gcc-ee3ae4f768dca3e67388018ee438c420eff43885.tar.bz2 | |
re PR libgcc/55451 (FAIL: gcc.dg/fixed-point/unary.c)
PR libgcc/55451
* fixed-bit.c (FIXED_SSADD, FIXED_SSSUB, FIXED_SSNEG): Avoid
undefined signed overflows.
From-SVN: r194439
Diffstat (limited to 'libgcc/fixed-bit.c')
| -rw-r--r-- | libgcc/fixed-bit.c | 29 |
1 files changed, 11 insertions, 18 deletions
diff --git a/libgcc/fixed-bit.c b/libgcc/fixed-bit.c index 84e5815..71243c1 100644 --- a/libgcc/fixed-bit.c +++ b/libgcc/fixed-bit.c @@ -1,5 +1,5 @@ /* This is a software fixed-point library. - Copyright (C) 2007, 2009, 2011 Free Software Foundation, Inc. + Copyright (C) 2007, 2009, 2011, 2012 Free Software Foundation, Inc. This file is part of GCC. @@ -80,15 +80,14 @@ FIXED_SSADD (FIXED_C_TYPE a, FIXED_C_TYPE b) INT_C_TYPE x, y, z; memcpy (&x, &a, FIXED_SIZE); memcpy (&y, &b, FIXED_SIZE); - z = x + y; + z = x + (UINT_C_TYPE) y; if ((((x ^ y) >> I_F_BITS) & 1) == 0) { if (((z ^ x) >> I_F_BITS) & 1) { - z = 1; - z = z << I_F_BITS; - if (x >= 0) - z--; + z = ((UINT_C_TYPE) 1) << I_F_BITS; + if (x >= 0) + z -= (UINT_C_TYPE) 1; } } #if HAVE_PADDING_BITS @@ -152,15 +151,14 @@ FIXED_SSSUB (FIXED_C_TYPE a, FIXED_C_TYPE b) INT_C_TYPE x, y, z; memcpy (&x, &a, FIXED_SIZE); memcpy (&y, &b, FIXED_SIZE); - z = x - y; + z = x - (UINT_C_TYPE) y; if (((x ^ y) >> I_F_BITS) & 1) { if (((z ^ x) >> I_F_BITS) & 1) { - z = 1; - z = z << I_F_BITS; - if (x >= 0) - z--; + z = ((UINT_C_TYPE) 1) << I_F_BITS; + if (x >= 0) + z -= (UINT_C_TYPE) 1; } } #if HAVE_PADDING_BITS @@ -569,16 +567,11 @@ FIXED_SSNEG (FIXED_C_TYPE a) INT_C_TYPE x, y, z; memcpy (&y, &a, FIXED_SIZE); x = 0; - z = x - y; + z = x - (UINT_C_TYPE) y; if (((x ^ y) >> I_F_BITS) & 1) { if (((z ^ x) >> I_F_BITS) & 1) - { - z = 1; - z = z << I_F_BITS; - if (x >= 0) - z--; - } + z = (((UINT_C_TYPE) 1) << I_F_BITS) - 1; } #if HAVE_PADDING_BITS z = z << PADDING_BITS; |