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| author | Jakub Jelinek <jakub@redhat.com> | 2021-12-28 17:41:24 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2021-12-28 17:41:24 +0100 |
| commit | 9258ac53cfcbe546e8b86a433e59343538743f74 (patch) | |
| tree | 8bbf5d5db4bc08119c925088e715f374cd84d027 /gcc | |
| parent | 3c5fd3616f73fbcd241cc3a5e09275c2b0c49bd4 (diff) | |
| download | gcc-9258ac53cfcbe546e8b86a433e59343538743f74.zip gcc-9258ac53cfcbe546e8b86a433e59343538743f74.tar.gz gcc-9258ac53cfcbe546e8b86a433e59343538743f74.tar.bz2 | |
fold-const: Fix up fold_truth_andor_1 shift handling [PR103813]
Some time ago I've changed const_binop -> wide_int_binop, so that it punts
on shifts by negative count. fold_truth_andor_1 doesn't check the results
of const_binop (?SHIFT_EXPR, ) though and assumes they will be always
non-NULL, which is no longer the case.
2021-12-28 Jakub Jelinek <jakub@redhat.com>
PR middle-end/103813
* fold-const.c (fold_truth_andor_1): Punt of const_binop LSHIFT_EXPR
or RSHIFT_EXPR returns NULL. Formatting fix.
* gcc.c-torture/compile/pr103813.c: New test.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/fold-const.c | 14 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.c-torture/compile/pr103813.c | 10 |
2 files changed, 22 insertions, 2 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 0b9a42f..14aa9ca 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -6454,15 +6454,19 @@ fold_truth_andor_1 (location_t loc, enum tree_code code, tree truth_type, size_int (xll_bitpos)); rl_mask = const_binop (LSHIFT_EXPR, fold_convert_loc (loc, lntype, rl_mask), size_int (xrl_bitpos)); + if (ll_mask == NULL_TREE || rl_mask == NULL_TREE) + return 0; if (l_const) { l_const = fold_convert_loc (loc, lntype, l_const); l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask); l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos)); + if (l_const == NULL_TREE) + return 0; if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const, fold_build1_loc (loc, BIT_NOT_EXPR, - lntype, ll_mask)))) + lntype, ll_mask)))) { warning (0, "comparison is always %d", wanted_code == NE_EXPR); @@ -6474,9 +6478,11 @@ fold_truth_andor_1 (location_t loc, enum tree_code code, tree truth_type, r_const = fold_convert_loc (loc, lntype, r_const); r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask); r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos)); + if (r_const == NULL_TREE) + return 0; if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const, fold_build1_loc (loc, BIT_NOT_EXPR, - lntype, rl_mask)))) + lntype, rl_mask)))) { warning (0, "comparison is always %d", wanted_code == NE_EXPR); @@ -6521,6 +6527,8 @@ fold_truth_andor_1 (location_t loc, enum tree_code code, tree truth_type, rr_mask = const_binop (LSHIFT_EXPR, fold_convert_loc (loc, rntype, rr_mask), size_int (xrr_bitpos)); + if (lr_mask == NULL_TREE || rr_mask == NULL_TREE) + return 0; /* Make a mask that corresponds to both fields being compared. Do this for both items being compared. If the operands are the @@ -6580,6 +6588,8 @@ fold_truth_andor_1 (location_t loc, enum tree_code code, tree truth_type, size_int (MIN (xll_bitpos, xrl_bitpos))); lr_mask = const_binop (RSHIFT_EXPR, lr_mask, size_int (MIN (xlr_bitpos, xrr_bitpos))); + if (ll_mask == NULL_TREE || lr_mask == NULL_TREE) + return 0; /* Convert to the smaller type before masking out unwanted bits. */ type = lntype; diff --git a/gcc/testsuite/gcc.c-torture/compile/pr103813.c b/gcc/testsuite/gcc.c-torture/compile/pr103813.c new file mode 100644 index 0000000..b3fc066 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/compile/pr103813.c @@ -0,0 +1,10 @@ +/* PR middle-end/103813 */ + +struct A { char b; char c[0x21000000]; }; +struct A d; + +int +foo () +{ + return d.c[0x20000000] || d.c[1]; +} |