From: Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org>
To: gcc Patches <gcc-patches@gcc.gnu.org>,
Richard Sandiford <richard.sandiford@arm.com>
Subject: ICE after folding svld1rq to vec_perm_expr duing forwprop
Date: Wed, 13 Jul 2022 00:41:04 +0530 [thread overview]
Message-ID: <CAAgBjMmC1EX7AvzPVcn86ZqhcZJtXGx16yEDkB2qSkJ_i09sAQ@mail.gmail.com> (raw)
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Hi Richard,
For the following test:
svint32_t f2(int a, int b, int c, int d)
{
int32x4_t v = (int32x4_t) {a, b, c, d};
return svld1rq_s32 (svptrue_b8 (), &v[0]);
}
The compiler emits following ICE with -O3 -mcpu=generic+sve:
foo.c: In function ‘f2’:
foo.c:4:11: error: non-trivial conversion in ‘view_convert_expr’
4 | svint32_t f2(int a, int b, int c, int d)
| ^~
svint32_t
__Int32x4_t
_7 = VIEW_CONVERT_EXPR<__Int32x4_t>(_8);
during GIMPLE pass: forwprop
dump file: foo.c.109t.forwprop2
foo.c:4:11: internal compiler error: verify_gimple failed
0xfda04a verify_gimple_in_cfg(function*, bool)
../../gcc/gcc/tree-cfg.cc:5568
0xe9371f execute_function_todo
../../gcc/gcc/passes.cc:2091
0xe93ccb execute_todo
../../gcc/gcc/passes.cc:2145
This happens because, after folding svld1rq_s32 to vec_perm_expr, we have:
int32x4_t v;
__Int32x4_t _1;
svint32_t _9;
vector(4) int _11;
<bb 2> :
_1 = {a_3(D), b_4(D), c_5(D), d_6(D)};
v_12 = _1;
_11 = v_12;
_9 = VEC_PERM_EXPR <_11, _11, { 0, 1, 2, 3, ... }>;
return _9;
During forwprop, simplify_permutation simplifies vec_perm_expr to
view_convert_expr,
and the end result becomes:
svint32_t _7;
__Int32x4_t _8;
;; basic block 2, loop depth 0
;; pred: ENTRY
_8 = {a_2(D), b_3(D), c_4(D), d_5(D)};
_7 = VIEW_CONVERT_EXPR<__Int32x4_t>(_8);
return _7;
;; succ: EXIT
which causes the error duing verify_gimple since VIEW_CONVERT_EXPR
has incompatible types (svint32_t, int32x4_t).
The attached patch disables simplification of VEC_PERM_EXPR
in simplify_permutation, if lhs and rhs have non compatible types,
which resolves ICE, but am not sure if it's the correct approach ?
Alternatively, should we allow assignments from fixed-width to SVE
vector, so the above
VIEW_CONVERT_EXPR would result in dup ?
Thanks,
Prathamesh
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diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
index 69567ab3275..be888f1c48e 100644
--- a/gcc/tree-ssa-forwprop.cc
+++ b/gcc/tree-ssa-forwprop.cc
@@ -2414,6 +2414,9 @@ simplify_permutation (gimple_stmt_iterator *gsi)
if (TREE_CODE (op2) != VECTOR_CST)
return 0;
+ if (!types_compatible_p (TREE_TYPE (gimple_get_lhs (stmt)), TREE_TYPE (op0)))
+ return 0;
+
if (TREE_CODE (op0) == VECTOR_CST)
{
code = VECTOR_CST;
next reply other threads:[~2022-07-12 19:11 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-12 19:11 Prathamesh Kulkarni [this message]
2022-07-13 6:51 ` Richard Biener
2022-07-14 7:54 ` Prathamesh Kulkarni
2022-07-14 8:33 ` Richard Biener
2022-07-14 11:52 ` Richard Sandiford
2022-07-15 13:48 ` Prathamesh Kulkarni
2022-07-18 6:27 ` Richard Biener
2022-07-20 15:35 ` Prathamesh Kulkarni
2022-07-21 6:51 ` Richard Biener
2022-08-01 3:16 ` Prathamesh Kulkarni
2022-08-08 8:56 ` Richard Biener
2022-08-09 10:09 ` Prathamesh Kulkarni
2022-08-09 13:12 ` Richard Biener
2022-08-11 13:23 ` Prathamesh Kulkarni
2022-08-16 16:30 ` Richard Sandiford
2022-08-17 11:31 ` Richard Biener
2022-08-18 12:44 ` Prathamesh Kulkarni
2022-08-18 12:50 ` Prathamesh Kulkarni
2022-08-29 6:23 ` Prathamesh Kulkarni
2022-09-05 8:54 ` Prathamesh Kulkarni
2022-09-05 9:09 ` Richard Biener
2022-09-05 9:26 ` Prathamesh Kulkarni
2022-09-05 11:03 ` Richard Biener
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