From 567fb6602c70e0c7341a0b1a39b017419669027b Mon Sep 17 00:00:00 2001 From: Kazu Hirata Date: Sun, 26 Jun 2005 03:49:20 +0000 Subject: [PATCH] re PR tree-optimization/22026 (ACATS FAIL C45331A fixed point wrong code (VRP related)) gcc/ PR tree-optimization/22026 * tree-vrp.c (extract_range_from_binary_expr): Drop to VR_VARYING if a binary expression involving VR_ANTI_RANGE is PLUS_EXPR, MINUS_EXPR, or unsigned MULT_EXPR. testsuite/ PR tree-optimization/22026 * gcc.dg/tree-ssa/pr22026.c: New. From-SVN: r101328 --- gcc/ChangeLog | 9 ++++- gcc/testsuite/ChangeLog | 5 +++ gcc/testsuite/gcc.dg/tree-ssa/pr22026.c | 49 +++++++++++++++++++++++++ gcc/tree-vrp.c | 42 +++++++++++++++++++++ 4 files changed, 104 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr22026.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 6c7bb98b43d..18c7e41ea01 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,4 +1,11 @@ -2005-06-25 Kazu Hirata +2005-06-26 Kazu Hirata + + PR tree-optimization/22026 + * tree-vrp.c (extract_range_from_binary_expr): Drop to + VR_VARYING if a binary expression involving VR_ANTI_RANGE is + PLUS_EXPR, MINUS_EXPR, or unsigned MULT_EXPR. + +2005-06-26 Kazu Hirata * Makefile.in (OBJS-common): Remove duplicate object file names. diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 419e012bd44..71961848bd3 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2005-06-26 Kazu Hirata + + PR tree-optimization/22026 + * gcc.dg/tree-ssa/pr22026.c: New. + 2005-06-25 Thomas Koenig PR libfortran/21144 diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr22026.c b/gcc/testsuite/gcc.dg/tree-ssa/pr22026.c new file mode 100644 index 00000000000..e56e4a124ad --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr22026.c @@ -0,0 +1,49 @@ +/* PR tree-optimization/22026 + VRP used think that ~[0,0] + ~[0,0] = ~[0,0], which is wrong. The + same applies to subtraction and unsigned multiplication. */ + +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-vrp" } */ + +int +plus (int x, int y) +{ + if (x != 0) + if (y != 0) + { + int z = x + y; + if (z != 0) + return 1; + } + return 0; +} + +int +minus (int x, int y) +{ + if (x != 0) + if (y != 0) + { + int z = x - y; + if (z != 0) + return 1; + } + return 0; +} + +int +mult (unsigned x, unsigned y) +{ + if (x != 0) + if (y != 0) + { + unsigned z = x * y; + if (z != 0) + return 1; + } + return 0; +} + +/* None of the predicates can be folded in these functions. */ +/* { dg-final { scan-tree-dump-times "Folding predicate" 0 "vrp" } } */ +/* { dg-final { cleanup-tree-dump "vrp" } } */ diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index 37bcb1b26c9..e733a8de7b9 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -1107,6 +1107,19 @@ extract_range_from_binary_expr (value_range_t *vr, tree expr) || code == MIN_EXPR || code == MAX_EXPR) { + /* If we have a PLUS_EXPR with two VR_ANTI_RANGEs, drop to + VR_VARYING. It would take more effort to compute a precise + range for such a case. For example, if we have op0 == 1 and + op1 == -1 with their ranges both being ~[0,0], we would have + op0 + op1 == 0, so we cannot claim that the sum is in ~[0,0]. + Note that we are guaranteed to have vr0.type == vr1.type at + this point. */ + if (code == PLUS_EXPR && vr0.type == VR_ANTI_RANGE) + { + set_value_range_to_varying (vr); + return; + } + /* For operations that make the resulting range directly proportional to the original ranges, apply the operation to the same end of each range. */ @@ -1123,6 +1136,22 @@ extract_range_from_binary_expr (value_range_t *vr, tree expr) tree val[4]; size_t i; + /* If we have an unsigned MULT_EXPR with two VR_ANTI_RANGEs, + drop to VR_VARYING. It would take more effort to compute a + precise range for such a case. For example, if we have + op0 == 65536 and op1 == 65536 with their ranges both being + ~[0,0] on a 32-bit machine, we would have op0 * op1 == 0, so + we cannot claim that the product is in ~[0,0]. Note that we + are guaranteed to have vr0.type == vr1.type at this + point. */ + if (code == MULT_EXPR + && vr0.type == VR_ANTI_RANGE + && (flag_wrapv || TYPE_UNSIGNED (TREE_TYPE (op0)))) + { + set_value_range_to_varying (vr); + return; + } + /* Multiplications and divisions are a bit tricky to handle, depending on the mix of signs we have in the two ranges, we need to operate on different values to get the minimum and @@ -1188,6 +1217,19 @@ extract_range_from_binary_expr (value_range_t *vr, tree expr) } else if (code == MINUS_EXPR) { + /* If we have a MINUS_EXPR with two VR_ANTI_RANGEs, drop to + VR_VARYING. It would take more effort to compute a precise + range for such a case. For example, if we have op0 == 1 and + op1 == 1 with their ranges both being ~[0,0], we would have + op0 - op1 == 0, so we cannot claim that the difference is in + ~[0,0]. Note that we are guaranteed to have + vr0.type == vr1.type at this point. */ + if (vr0.type == VR_ANTI_RANGE) + { + set_value_range_to_varying (vr); + return; + } + /* For MINUS_EXPR, apply the operation to the opposite ends of each range. */ min = vrp_int_const_binop (code, vr0.min, vr1.max); -- 2.30.2