This fixes the first part of SLSR incorrectly inserting undefined code
(overflow)
into the IR. The easiest way is to rewrite the statement after creating it
using rewrite_to_defined_unconditional.
This fixes the testcases from PR 121347 (and a few others) which all cause an
infinite loops to appear.
I will be posting the fix for replace_rhs_if_not_dup later and at that point I
will add a few testcases.
Bootstrapped and tested on x86_64-linux-gnu with no regressions.
PR tree-optimization/121347
PR tree-optimization/106883
gcc/ChangeLog:
* gimple-ssa-strength-reduction.cc (insert_initializers): Rewrite
newly inserted statements for undefinedness (overflow).
Signed-off-by: Andrew Pinski <[email protected]>
---
gcc/gimple-ssa-strength-reduction.cc | 31 +++++++++++++++++++++++-----
1 file changed, 26 insertions(+), 5 deletions(-)
diff --git a/gcc/gimple-ssa-strength-reduction.cc
b/gcc/gimple-ssa-strength-reduction.cc
index 70978b295d8..3bb924fa54c 100644
--- a/gcc/gimple-ssa-strength-reduction.cc
+++ b/gcc/gimple-ssa-strength-reduction.cc
@@ -57,6 +57,7 @@ along with GCC; see the file COPYING3. If not see
#include "tree-eh.h"
#include "builtins.h"
#include "tree-ssa-dce.h"
+#include "gimple-fold.h"
/* Information about a strength reduction candidate. Each statement
in the candidate table represents an expression of one of the
@@ -3474,8 +3475,15 @@ insert_initializers (slsr_cand_t c)
gimple_set_location (cast_stmt, loc);
}
- gsi_insert_before (&gsi, init_stmt, GSI_SAME_STMT);
gimple_set_location (init_stmt, loc);
+ if (gimple_needing_rewrite_undefined (init_stmt))
+ {
+ gimple_seq seq;
+ seq = rewrite_to_defined_unconditional (init_stmt);
+ gsi_insert_seq_before (&gsi, seq, GSI_SAME_STMT);
+ }
+ else
+ gsi_insert_before (&gsi, init_stmt, GSI_SAME_STMT);
}
else
{
@@ -3483,6 +3491,7 @@ insert_initializers (slsr_cand_t c)
gimple *basis_stmt = lookup_cand (c->basis)->cand_stmt;
location_t loc = gimple_location (basis_stmt);
+ gimple_set_location (init_stmt, gimple_location (basis_stmt));
if (!gsi_end_p (gsi) && stmt_ends_bb_p (gsi_stmt (gsi)))
{
if (cast_stmt)
@@ -3490,7 +3499,14 @@ insert_initializers (slsr_cand_t c)
gsi_insert_before (&gsi, cast_stmt, GSI_SAME_STMT);
gimple_set_location (cast_stmt, loc);
}
- gsi_insert_before (&gsi, init_stmt, GSI_SAME_STMT);
+ if (gimple_needing_rewrite_undefined (init_stmt))
+ {
+ gimple_seq seq;
+ seq = rewrite_to_defined_unconditional (init_stmt);
+ gsi_insert_seq_before (&gsi, seq, GSI_SAME_STMT);
+ }
+ else
+ gsi_insert_before (&gsi, init_stmt, GSI_SAME_STMT);
}
else
{
@@ -3499,10 +3515,15 @@ insert_initializers (slsr_cand_t c)
gsi_insert_after (&gsi, cast_stmt, GSI_NEW_STMT);
gimple_set_location (cast_stmt, loc);
}
- gsi_insert_after (&gsi, init_stmt, GSI_NEW_STMT);
+ if (gimple_needing_rewrite_undefined (init_stmt))
+ {
+ gimple_seq seq;
+ seq = rewrite_to_defined_unconditional (init_stmt);
+ gsi_insert_seq_after (&gsi, seq, GSI_SAME_STMT);
+ }
+ else
+ gsi_insert_after (&gsi, init_stmt, GSI_SAME_STMT);
}
-
- gimple_set_location (init_stmt, gimple_location (basis_stmt));
}
if (dump_file && (dump_flags & TDF_DETAILS))
--
2.43.0
