Introduce REG_SET_EMPTY_P
Commit Message
This avoids a -Wunreachable-code diagnostic with EXECUTE_IF_*
in case the first iteration will exit the loop. For the case
in thread_jump using bitmap_empty_p looks preferable so this
adds REG_SET_EMPTY_P to make that available for register sets.
Bootstrapped and tested on x86_64-unknown-linux-gnu, will push.
Richard.
2021-11-25 Richard Biener <rguenther@suse.de>
* regset.h (REG_SET_EMPTY_P): New macro.
* cfgcleanup.c (thread_jump): Use REG_SET_EMPTY_P.
---
gcc/cfgcleanup.c | 3 +--
gcc/regset.h | 3 +++
2 files changed, 4 insertions(+), 2 deletions(-)
@@ -256,7 +256,6 @@ thread_jump (edge e, basic_block b)
unsigned i;
regset nonequal;
bool failed = false;
- reg_set_iterator rsi;
/* Jump threading may cause fixup_partitions to introduce new crossing edges,
which is not allowed after reload. */
@@ -379,7 +378,7 @@ thread_jump (edge e, basic_block b)
goto failed_exit;
}
- EXECUTE_IF_SET_IN_REG_SET (nonequal, 0, i, rsi)
+ if (!REG_SET_EMPTY_P (nonequal))
goto failed_exit;
BITMAP_FREE (nonequal);
@@ -49,6 +49,9 @@ typedef bitmap regset;
/* Clear a register set by freeing up the linked list. */
#define CLEAR_REG_SET(HEAD) bitmap_clear (HEAD)
+/* True if the register set is empty. */
+#define REG_SET_EMPTY_P(HEAD) bitmap_empty_p (HEAD)
+
/* Copy a register set to another register set. */
#define COPY_REG_SET(TO, FROM) bitmap_copy (TO, FROM)