From fe1e7d0e9b7479f13b84670ac3b56cf5244d877c Mon Sep 17 00:00:00 2001 From: Eric Botcazou Date: Wed, 19 Apr 2017 19:27:09 +0000 Subject: [PATCH] re PR tree-optimization/80426 (wrong manipulation of range based on INT_MIN) PR tree-optimization/80426 * tree-vrp.c (extract_range_from_binary_expr_1): For an additive operation on symbolic operands, also compute the overflow for the invariant part when the operation degenerates into a negation. PR tree-optimization/80426 * gcc.c-torture/execute/20170419-1.c: New test. Co-Authored-By: Jakub Jelinek From-SVN: r247007 --- gcc/ChangeLog | 8 +++++ gcc/testsuite/ChangeLog | 5 ++++ .../gcc.c-torture/execute/20170429-1.c | 24 +++++++++++++++ gcc/tree-vrp.c | 30 +++++++++++++++++-- 4 files changed, 65 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/gcc.c-torture/execute/20170429-1.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 6b17e9a8b87..de76f8a83f4 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2017-04-19 Eric Botcazou + Jakub Jelinek + + PR tree-optimization/80426 + * tree-vrp.c (extract_range_from_binary_expr_1): For an additive + operation on symbolic operands, also compute the overflow for the + invariant part when the operation degenerates into a negation. + 2017-04-19 Jakub Jelinek PR debug/80461 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 048541d3107..7c306a683e9 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-04-19 Eric Botcazou + + PR tree-optimization/80426 + * gcc.c-torture/execute/20170419-1.c: New test. + 2017-04-19 Jakub Jelinek PR debug/80461 diff --git a/gcc/testsuite/gcc.c-torture/execute/20170429-1.c b/gcc/testsuite/gcc.c-torture/execute/20170429-1.c new file mode 100644 index 00000000000..f59dbc7a057 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/execute/20170429-1.c @@ -0,0 +1,24 @@ +/* PR tree-optimization/80426 */ +/* Testcase by */ + +#define INT_MAX 0x7fffffff +#define INT_MIN (-INT_MAX-1) + +int x; + +int main (void) +{ + volatile int a = 0; + volatile int b = -INT_MAX; + int j; + + for(j = 0; j < 18; j += 1) { + x = ( (a == 0) != (b - (int)(INT_MIN) ) ); + } + + if (x != 0) + __builtin_abort (); + + return 0; +} + diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index 6d802de29a8..697cd88502e 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -2461,7 +2461,20 @@ extract_range_from_binary_expr_1 (value_range *vr, else if (min_op0) wmin = min_op0; else if (min_op1) - wmin = minus_p ? wi::neg (min_op1) : min_op1; + { + if (minus_p) + { + wmin = wi::neg (min_op1); + + /* Check for overflow. */ + if (sgn == SIGNED && wi::neg_p (min_op1) && wi::neg_p (wmin)) + min_ovf = 1; + else if (sgn == UNSIGNED && wi::ne_p (min_op1, 0)) + min_ovf = -1; + } + else + wmin = min_op1; + } else wmin = wi::shwi (0, prec); @@ -2489,7 +2502,20 @@ extract_range_from_binary_expr_1 (value_range *vr, else if (max_op0) wmax = max_op0; else if (max_op1) - wmax = minus_p ? wi::neg (max_op1) : max_op1; + { + if (minus_p) + { + wmax = wi::neg (max_op1); + + /* Check for overflow. */ + if (sgn == SIGNED && wi::neg_p (max_op1) && wi::neg_p (wmax)) + max_ovf = 1; + else if (sgn == UNSIGNED && wi::ne_p (max_op1, 0)) + max_ovf = -1; + } + else + wmax = max_op1; + } else wmax = wi::shwi (0, prec); -- 2.30.2