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author | Aldy Hernandez <aldyh@redhat.com> | 2020-10-19 09:48:27 +0200 |
---|---|---|
committer | Aldy Hernandez <aldyh@redhat.com> | 2020-10-19 11:37:15 +0200 |
commit | 5b80069c7e65a3ed60ee16deac4a450a9c32efa6 (patch) | |
tree | 5fb15f141f9210cc3000530128906284d1eccf2f /gcc | |
parent | 95f27849a580ac834d4f51a0642da9671f0a9dee (diff) | |
download | gcc-5b80069c7e65a3ed60ee16deac4a450a9c32efa6.zip gcc-5b80069c7e65a3ed60ee16deac4a450a9c32efa6.tar.gz gcc-5b80069c7e65a3ed60ee16deac4a450a9c32efa6.tar.bz2 |
Handle right shifts by zero in range-ops.
If the shift amount in operator_lshift::op1_range was zero, an invalid range
of [1, 0] was being created.
gcc/ChangeLog:
PR tree-optimization/97467
* range-op.cc (operator_lshift::op1_range): Handle shifts by 0.
gcc/testsuite/ChangeLog:
* gcc.dg/pr97467.c: New test.
Diffstat (limited to 'gcc')
-rw-r--r-- | gcc/range-op.cc | 5 | ||||
-rw-r--r-- | gcc/testsuite/gcc.dg/pr97467.c | 16 |
2 files changed, 21 insertions, 0 deletions
diff --git a/gcc/range-op.cc b/gcc/range-op.cc index 0efa001..30d2a4d 100644 --- a/gcc/range-op.cc +++ b/gcc/range-op.cc @@ -1579,6 +1579,11 @@ operator_lshift::op1_range (irange &r, wide_int shift = wi::to_wide (shift_amount); if (wi::lt_p (shift, 0, SIGNED)) return false; + if (shift == 0) + { + r = lhs; + return true; + } // Work completely in unsigned mode to start. tree utype = type; diff --git a/gcc/testsuite/gcc.dg/pr97467.c b/gcc/testsuite/gcc.dg/pr97467.c new file mode 100644 index 0000000..dcbd218 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr97467.c @@ -0,0 +1,16 @@ +/* { dg-do compile } */ +/* { dg-options "-Os" } */ + +int a; +long b; +unsigned int c = 1; + +int main () { + int e; + for (; c <= 0; c++) { + int f = 0; + b = e; + a = f || b << c; + } + return 0; +} |