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| author | Andrew Pinski <quic_apinski@quicinc.com> | 2024-11-08 14:46:18 -0800 |
|---|---|---|
| committer | Andrew Pinski <quic_apinski@quicinc.com> | 2024-11-09 08:21:25 -0800 |
| commit | ed88bc2344321ee21e92afdd83b50699c4e4df79 (patch) | |
| tree | 0f3c0384cd46ba682a1c1d027d3ae57138ef5df6 /gcc | |
| parent | 6e84a41622f56ca360d995e6092ded3b5a02ba40 (diff) | |
| download | gcc-ed88bc2344321ee21e92afdd83b50699c4e4df79.zip gcc-ed88bc2344321ee21e92afdd83b50699c4e4df79.tar.gz gcc-ed88bc2344321ee21e92afdd83b50699c4e4df79.tar.bz2 | |
fold: Remove (rrotate (rrotate A CST) CST) folding [PR117492]
This removes an (broken) simplification from fold which is already handled in match.
The reason why it was broken is because of the use of wi::to_wide on the RHS of the
rotate which could be 2 different types even though the LHS was the same type.
Since it is already handled in match (by the patterns for
`Turn (a OP c1) OP c2 into a OP (c1+c2).`). It can be removed without losing any optimizations.
Bootstrapped and tested on x86_64-linux-gnu.
PR middle-end/117492
gcc/ChangeLog:
* fold-const.cc (fold_binary_loc): Remove `Two consecutive rotates adding up
to the some integer` simplifcation.
gcc/testsuite/ChangeLog:
* gcc.dg/torture/pr117492-1.c: New test.
Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/fold-const.cc | 10 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr117492-1.c | 16 |
2 files changed, 16 insertions, 10 deletions
diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc index 0e37429..1e8ae1a 100644 --- a/gcc/fold-const.cc +++ b/gcc/fold-const.cc @@ -12530,16 +12530,6 @@ fold_binary_loc (location_t loc, enum tree_code code, tree type, arg01, arg1)); } - /* Two consecutive rotates adding up to the some integer - multiple of the precision of the type can be ignored. */ - if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST - && TREE_CODE (arg0) == RROTATE_EXPR - && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST - && wi::umod_trunc (wi::to_wide (arg1) - + wi::to_wide (TREE_OPERAND (arg0, 1)), - prec) == 0) - return fold_convert_loc (loc, type, TREE_OPERAND (arg0, 0)); - return NULL_TREE; case MIN_EXPR: diff --git a/gcc/testsuite/gcc.dg/torture/pr117492-1.c b/gcc/testsuite/gcc.dg/torture/pr117492-1.c new file mode 100644 index 0000000..543d8b7 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr117492-1.c @@ -0,0 +1,16 @@ +/* { dg-do compile } */ +/* PR middle-end/117492 */ + +/* This code would ICE in fold due to code which was using wi::to_wide with different types + and adding them. */ + +typedef unsigned u; + +u +foo(u x) +{ + return + __builtin_stdc_rotate_left((unsigned) + __builtin_stdc_rotate_right(x, 0x100000001ull), + 1); +} |