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| author | Kugan Vivekanandarajah <kuganv@linaro.org> | 2016-07-29 00:35:23 +0000 |
|---|---|---|
| committer | Kugan Vivekanandarajah <kugan@gcc.gnu.org> | 2016-07-29 00:35:23 +0000 |
| commit | 883b6d4e1b1c826007d12b4685b4e7b0fffc5347 (patch) | |
| tree | 19f8f9d123989dcab239ef62675ca3ca7bd10f0a /gcc/tree-vrp.c | |
| parent | 257490974f36d660237ea0f6809b9c8b7f2b1461 (diff) | |
| download | gcc-883b6d4e1b1c826007d12b4685b4e7b0fffc5347.zip gcc-883b6d4e1b1c826007d12b4685b4e7b0fffc5347.tar.gz gcc-883b6d4e1b1c826007d12b4685b4e7b0fffc5347.tar.bz2 | |
re PR rtl-optimization/68217 (Wrong constant folding)
gcc/ChangeLog:
2016-07-29 Kugan Vivekanandarajah <kuganv@linaro.org>
PR middle-end/68217
* tree-vrp.c (extract_range_from_binary_expr_1): In case of signed
& sign-bit-CST, generate [-INF, 0] instead of [-INF, INF].
gcc/testsuite/ChangeLog:
2016-07-29 Kugan Vivekanandarajah <kuganv@linaro.org>
PR middle-end/68217
* gcc.dg/pr68217.c: New test.
From-SVN: r238846
Diffstat (limited to 'gcc/tree-vrp.c')
| -rw-r--r-- | gcc/tree-vrp.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index 77c3014..41c870f 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -3067,6 +3067,24 @@ extract_range_from_binary_expr_1 (value_range *vr, if (int_cst_range1 && tree_int_cst_sgn (vr1.min) >= 0) wmax = wi::min (wmax, vr1.max, TYPE_SIGN (expr_type)); max = wide_int_to_tree (expr_type, wmax); + cmp = compare_values (min, max); + /* PR68217: In case of signed & sign-bit-CST should + result in [-INF, 0] instead of [-INF, INF]. */ + if (cmp == -2 || cmp == 1) + { + wide_int sign_bit + = wi::set_bit_in_zero (TYPE_PRECISION (expr_type) - 1, + TYPE_PRECISION (expr_type)); + if (!TYPE_UNSIGNED (expr_type) + && ((value_range_constant_singleton (&vr0) + && !wi::cmps (vr0.min, sign_bit)) + || (value_range_constant_singleton (&vr1) + && !wi::cmps (vr1.min, sign_bit)))) + { + min = TYPE_MIN_VALUE (expr_type); + max = build_int_cst (expr_type, 0); + } + } } else if (code == BIT_IOR_EXPR) { |