diff options
author | Richard Biener <rguenther@suse.de> | 2014-05-05 09:23:31 +0000 |
---|---|---|
committer | Richard Biener <rguenther@suse.de> | 2014-05-05 09:23:31 +0000 |
commit | 354b6cf1f10a4f8d2b5d4031c4e4bdd8c2c3532b (patch) | |
tree | f757276d245dcc7de0472ece3f970911675fca65 | |
parent | b9017f665a28f7e8da6c3d72c1a8d06117c5fda9 (diff) |
2014-05-05 Richard Biener <rguenther@suse.de>
PR middle-end/61010
* fold-const.c (fold_binary_loc): Consistently avoid
canonicalizing X & CST away from a CST that is the mask
of a mode.
* gcc.dg/torture/pr61010.c: New testcase.
git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@210066 138bc75d-0d04-0410-961f-82ee72b054a4
-rw-r--r-- | gcc/ChangeLog | 7 | ||||
-rw-r--r-- | gcc/fold-const.c | 33 | ||||
-rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
-rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr61010.c | 8 |
4 files changed, 34 insertions, 19 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index a3cd478d5b7..18959f6eacb 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2014-05-05 Richard Biener <rguenther@suse.de> + + PR middle-end/61010 + * fold-const.c (fold_binary_loc): Consistently avoid + canonicalizing X & CST away from a CST that is the mask + of a mode. + 2014-05-05 Jan-Benedict Glaw <jbglaw@lug-owl.de> * config/picochip/picochip-protos.h (picochip_regno_nregs): Change diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 5c2bf256c2a..65051a12c2a 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -11426,7 +11426,6 @@ fold_binary_loc (location_t loc, { double_int c1, c2, c3, msk; int width = TYPE_PRECISION (type), w; - bool try_simplify = true; c1 = tree_to_double_int (TREE_OPERAND (arg0, 1)); c2 = tree_to_double_int (arg1); @@ -11463,20 +11462,7 @@ fold_binary_loc (location_t loc, } } - /* If X is a tree of the form (Y * K1) & K2, this might conflict - with that optimization from the BIT_AND_EXPR optimizations. - This could end up in an infinite recursion. */ - if (TREE_CODE (TREE_OPERAND (arg0, 0)) == MULT_EXPR - && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)) - == INTEGER_CST) - { - tree t = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1); - double_int masked = mask_with_tz (type, c3, tree_to_double_int (t)); - - try_simplify = (masked != c1); - } - - if (try_simplify && c3 != c1) + if (c3 != c1) return fold_build2_loc (loc, BIT_IOR_EXPR, type, fold_build2_loc (loc, BIT_AND_EXPR, type, TREE_OPERAND (arg0, 0), @@ -11866,16 +11852,25 @@ fold_binary_loc (location_t loc, && TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST) { + double_int darg1 = tree_to_double_int (arg1); double_int masked - = mask_with_tz (type, tree_to_double_int (arg1), + = mask_with_tz (type, darg1, tree_to_double_int (TREE_OPERAND (arg0, 1))); if (masked.is_zero ()) return omit_two_operands_loc (loc, type, build_zero_cst (type), arg0, arg1); - else if (masked != tree_to_double_int (arg1)) - return fold_build2_loc (loc, code, type, op0, - double_int_to_tree (type, masked)); + else if (masked != darg1) + { + /* Avoid the transform if arg1 is a mask of some + mode which allows further optimizations. */ + int pop = darg1.popcount (); + if (!(pop >= BITS_PER_UNIT + && exact_log2 (pop) != -1 + && double_int::mask (pop) == darg1)) + return fold_build2_loc (loc, code, type, op0, + double_int_to_tree (type, masked)); + } } /* For constants M and N, if M == (1LL << cst) - 1 && (N & M) == M, diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index ce105724f69..1c9d4d31c66 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2014-05-05 Richard Biener <rguenther@suse.de> + + PR middle-end/61010 + * gcc.dg/torture/pr61010.c: New testcase. + 2014-05-05 Andreas Krebbel <Andreas.Krebbel@de.ibm.com> * gcc.target/s390/leaf-profile.c: New testcase. diff --git a/gcc/testsuite/gcc.dg/torture/pr61010.c b/gcc/testsuite/gcc.dg/torture/pr61010.c new file mode 100644 index 00000000000..ed5653982cb --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr61010.c @@ -0,0 +1,8 @@ +/* { dg-do compile } */ + +int main (void) +{ + int a = 0; + unsigned b = (a * 64 & 192) | 63U; + return 0; +} |