Hi The attached testcase triggers ICE when testing GCC trunk on aarch64 with -S -O2 -ftree-loop-vectorize -march=armv8.2-a+sve -msve-vector-bits=256.
Before the forwprop pass, we have two gimple statements as follows:
_43 = &MEM[base: _5, offset: 0B];
vect__2.7_24 = MEM <vector(8) int> [(int *)_43];
The forwprop pass tries to forward propgate the &MEM[base: _5, offset: 0B] to
the base of the MEM <vector(8) int> [(int *)_43]. Thus, we get a gimple
statement as follows:
vect__2.7_24 = MEM <vector(8) int> [(int *)&MEM[base: _5, offset: 0B]];
As the &MEM[base: _5, offset: 0B] is a ADDR_EXPR as well as a invalid address
for gimple MEM_REF, ICE triggers in function maybe_canonicalize_mem_ref_addr at
gcc/gimple-fold.c:4899 as follows:
gcc_checking_assert (TREE_CODE (TREE_OPERAND (*t, 0)) == DEBUG_EXPR_DECL
|| is_gimple_mem_ref_addr (TREE_OPERAND (*t, 0)));
where *t is the MEM <vector(8) int> [(int *)&MEM[base: _5, offset: 0B]] at that
time.
A simple solution is to add a check before forward propgating a ADDR_EXPR to a
MEM_REF.
Attached please find the proposed patch.
Newly add test fail without the patch and pass after applying the patch.
Bootstrap and tested on aarch64 and x86 Linux platform. No new regression
witnessed.
Any suggestion?
Thanks,
Qian Chao
Log:
+2020-03-23 Qian chao <qianch...@huawei.com>
+
+ PR c/94266
+ * gcc/tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Add check
before forward propgating ADDR_EXPR to the operand of MEM_REF.
gcc/testsuite:
+2020-03-23 Qian chao <qianch...@huawei.com>
+
+ PR c/94266
+ * gcc.target/aarch64/pr94266.c：New test.
pr94266-v0.patch
Description: pr94266-v0.patch
