lower-bitint, v2: Make temporarily wrong IL less wrong [PR112843]
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On Tue, Dec 05, 2023 at 08:21:15AM +0100, Jakub Jelinek wrote:
> The reason I tweaked the lhs first is that it then just uses gimple_op and
> iterates over all ops, if that is done before lhs it would need to special
> case which op to skip because it is lhs (I'm using gimple_get_lhs for the
> lhs, but this isn't done for GIMPLE_CALL nor GIMPLE_PHI, so GIMPLE_ASSIGN
> or say GIMPLE_GOTO etc. are the only options, so I could just start with
> op 1 rather than 0 for is_gimple_assign).
Here is a variant which adjusts the inputs first before set_lhs, then
addition of cast after it and finally update_stmt.
So far tested with
make check-gcc check-g++ -j32 -k GCC_TEST_RUN_EXPENSIVE=1 RUNTESTFLAGS="GCC_TEST_RUN_EXPENSIVE=1 dg.exp='*bitint* pr112673.c builtin-stdc-bit-*.c pr112566-2.c pr112511.c' dg-torture.exp=*bitint* dfp.exp=*bitint*"
2023-12-05 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/112843
* gimple-lower-bitint.cc (gimple_lower_bitint): Change lhs of stmt
to lhs2 before building and inserting lhs = (cast) lhs2; assignment.
Adjust stmt operands before adjusting lhs.
* gcc.dg/bitint-47.c: New test.
Jakub
@@ -6329,27 +6329,9 @@ gimple_lower_bitint (void)
tree type = NULL_TREE;
/* Middle _BitInt(N) is rewritten to casts to INTEGER_TYPEs
with the same precision and back. */
- if (tree lhs = gimple_get_lhs (stmt))
- if (TREE_CODE (TREE_TYPE (lhs)) == BITINT_TYPE
- && (bitint_precision_kind (TREE_TYPE (lhs))
- == bitint_prec_middle))
- {
- int prec = TYPE_PRECISION (TREE_TYPE (lhs));
- int uns = TYPE_UNSIGNED (TREE_TYPE (lhs));
- type = build_nonstandard_integer_type (prec, uns);
- tree lhs2 = make_ssa_name (type);
- gimple *g = gimple_build_assign (lhs, NOP_EXPR, lhs2);
- if (stmt_ends_bb_p (stmt))
- {
- edge e = find_fallthru_edge (gsi_bb (gsi)->succs);
- gsi_insert_on_edge_immediate (e, g);
- }
- else
- gsi_insert_after (&gsi, g, GSI_SAME_STMT);
- gimple_set_lhs (stmt, lhs2);
- }
unsigned int nops = gimple_num_ops (stmt);
- for (unsigned int i = 0; i < nops; ++i)
+ for (unsigned int i = is_gimple_assign (stmt) ? 1 : 0;
+ i < nops; ++i)
if (tree op = gimple_op (stmt, i))
{
tree nop = maybe_cast_middle_bitint (&gsi, op, type);
@@ -6376,6 +6358,25 @@ gimple_lower_bitint (void)
type);
}
}
+ if (tree lhs = gimple_get_lhs (stmt))
+ if (TREE_CODE (TREE_TYPE (lhs)) == BITINT_TYPE
+ && (bitint_precision_kind (TREE_TYPE (lhs))
+ == bitint_prec_middle))
+ {
+ int prec = TYPE_PRECISION (TREE_TYPE (lhs));
+ int uns = TYPE_UNSIGNED (TREE_TYPE (lhs));
+ type = build_nonstandard_integer_type (prec, uns);
+ tree lhs2 = make_ssa_name (type);
+ gimple_set_lhs (stmt, lhs2);
+ gimple *g = gimple_build_assign (lhs, NOP_EXPR, lhs2);
+ if (stmt_ends_bb_p (stmt))
+ {
+ edge e = find_fallthru_edge (gsi_bb (gsi)->succs);
+ gsi_insert_on_edge_immediate (e, g);
+ }
+ else
+ gsi_insert_after (&gsi, g, GSI_SAME_STMT);
+ }
update_stmt (stmt);
continue;
}
@@ -0,0 +1,13 @@
+/* PR tree-optimization/112843 */
+/* { dg-do compile { target bitint } } */
+/* { dg-options "-O2" } */
+
+#if __BITINT_MAXWIDTH__ >= 256
+_BitInt (256)
+foo (_BitInt (128) x, _BitInt (256) y)
+{
+ return x * 5 * y;
+}
+#else
+int x;
+#endif