This was an interesting compare debug failure to debug. The first symptom
was in gcse which would produce different order of creating psedu-registers.
This
was caused by a different order of a hashtable walk, due to the hash table
having different
number of entries. Which in turn was due to the number of max insn being
different between
the 2 runs. The place max insn uid comes from was in sh_recog_treg_set_expr
which is called
via rtx_costs and fwprop would cause rtx_costs in some cases for debug insn
related stuff.
Build and tested for sh4-linux-gnu.
PR target/116189
gcc/ChangeLog:
* config/sh/sh.cc (sh_recog_treg_set_expr): Don't call make_insn_raw,
make the insn with a fake uid.
gcc/testsuite/ChangeLog:
* c-c++-common/torture/pr116189-1.c: New test.
Signed-off-by: Andrew Pinski <[email protected]>
---
gcc/config/sh/sh.cc | 12 +++++++-
.../c-c++-common/torture/pr116189-1.c | 30 +++++++++++++++++++
2 files changed, 41 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/c-c++-common/torture/pr116189-1.c
diff --git a/gcc/config/sh/sh.cc b/gcc/config/sh/sh.cc
index bc017420381..7391b8df583 100644
--- a/gcc/config/sh/sh.cc
+++ b/gcc/config/sh/sh.cc
@@ -12297,7 +12297,17 @@ sh_recog_treg_set_expr (rtx op, machine_mode mode)
have to capture its current state and restore it afterwards. */
recog_data_d prev_recog_data = recog_data;
- rtx_insn* i = make_insn_raw (gen_rtx_SET (get_t_reg_rtx (), op));
+ /* Note we can't use insn_raw here since that increases the uid
+ and could cause debug compare differences; this insn never leaves
+ this function so create a dummy one. */
+ rtx_insn* i = as_a <rtx_insn *> (rtx_alloc (INSN));
+
+ INSN_UID (i) = 1;
+ PATTERN (i) = gen_rtx_SET (get_t_reg_rtx (), op);
+ INSN_CODE (i) = -1;
+ REG_NOTES (i) = NULL;
+ INSN_LOCATION (i) = curr_insn_location ();
+ BLOCK_FOR_INSN (i) = NULL;
SET_PREV_INSN (i) = NULL;
SET_NEXT_INSN (i) = NULL;
diff --git a/gcc/testsuite/c-c++-common/torture/pr116189-1.c
b/gcc/testsuite/c-c++-common/torture/pr116189-1.c
new file mode 100644
index 00000000000..055c563f43e
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/torture/pr116189-1.c
@@ -0,0 +1,30 @@
+/* { dg-additional-options "-fcompare-debug" } */
+
+/* PR target/116189 */
+
+/* In the sh backend, we used to create insn in the path of rtx_costs.
+ This means sometimes the max uid for insns would be different between
+ debugging and non debugging which then would cause gcse's hashtable
+ to have different number of slots which would cause a different walk
+ for that hash table. */
+
+extern void ff(void);
+extern short nn[8][4];
+typedef unsigned short move_table[4];
+extern signed long long ira_overall_cost;
+extern signed long long ira_load_cost;
+extern move_table *x_ira_register_move_cost[1];
+struct move { struct move *next; };
+unsigned short t;
+void emit_move_list(struct move * list, int freq, unsigned char mode, int
regno) {
+ int cost;
+ for (; list != 0; list = list->next)
+ {
+ ff();
+ unsigned short aclass = t;
+ cost = (nn)[mode][aclass] ;
+ ira_load_cost = cost;
+ cost = x_ira_register_move_cost[mode][aclass][aclass] * freq ;
+ ira_overall_cost = cost;
+ }
+}
--
2.43.0
