diff options
Diffstat (limited to 'gcc/lower-subreg.c')
| -rw-r--r-- | gcc/lower-subreg.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/gcc/lower-subreg.c b/gcc/lower-subreg.c index 160328ccefc..1cc972ac72d 100644 --- a/gcc/lower-subreg.c +++ b/gcc/lower-subreg.c @@ -63,6 +63,12 @@ static bitmap decomposable_context; which it can not be decomposed. */ static bitmap non_decomposable_context; +/* Bit N in this bitmap is set if regno N is used in a subreg + which changes the mode but not the size. This typically happens + when the register accessed as a floating-point value; we want to + avoid generating accesses to its subwords in integer modes. */ +static bitmap subreg_context; + /* Bit N in the bitmap in element M of this array is set if there is a copy from reg M to reg N. */ static VEC(bitmap,heap) *reg_copy_graph; @@ -289,6 +295,7 @@ find_decomposable_subregs (rtx *px, void *data) && !MODES_TIEABLE_P (GET_MODE (x), GET_MODE (inner))) { bitmap_set_bit (non_decomposable_context, regno); + bitmap_set_bit (subreg_context, regno); return -1; } } @@ -616,7 +623,7 @@ can_decompose_p (rtx x) return (validate_subreg (word_mode, GET_MODE (x), x, UNITS_PER_WORD) && HARD_REGNO_MODE_OK (regno, word_mode)); else - return !bitmap_bit_p (non_decomposable_context, regno); + return !bitmap_bit_p (subreg_context, regno); } return true; @@ -1091,6 +1098,7 @@ decompose_multiword_subregs (void) decomposable_context = BITMAP_ALLOC (NULL); non_decomposable_context = BITMAP_ALLOC (NULL); + subreg_context = BITMAP_ALLOC (NULL); reg_copy_graph = VEC_alloc (bitmap, heap, max); VEC_safe_grow (bitmap, heap, reg_copy_graph, max); @@ -1309,6 +1317,7 @@ decompose_multiword_subregs (void) BITMAP_FREE (decomposable_context); BITMAP_FREE (non_decomposable_context); + BITMAP_FREE (subreg_context); } /* Gate function for lower subreg pass. */ |