diff options
Diffstat (limited to 'gcc/rtlanal.c')
| -rw-r--r-- | gcc/rtlanal.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/gcc/rtlanal.c b/gcc/rtlanal.c index d5b203e..d1240b0 100644 --- a/gcc/rtlanal.c +++ b/gcc/rtlanal.c @@ -1458,11 +1458,13 @@ set_of (const_rtx pat, const_rtx insn) /* Check whether instruction pattern PAT contains a SET with the following properties: - - the SET is executed unconditionally; - - the destination of the SET is write-only rather than read-write; and + - the SET is executed unconditionally; and - either: - the destination of the SET is a REG that contains REGNO; or - - the destination of the SET is a SUBREG of such a REG. + - both: + - the destination of the SET is a SUBREG of such a REG; and + - writing to the subreg clobbers all of the SUBREG_REG + (in other words, read_modify_subreg_p is false). If PAT does have a SET like that, return the set, otherwise return null. |