When subregs contain promoted values, as indicated by
SUBREG_PROMOTED_VAR_P, both the unpromoted (outer) and
promoted (inner) values are known to be scalar integers.
This patch adds helper routines that get the modes as
scalar_int_modes.
gcc/
2016-11-24 Richard Sandiford <richard.sandif...@arm.com>
Alan Hayward <alan.hayw...@arm.com>
David Sherwood <david.sherw...@arm.com>
* rtl.h (subreg_unpromoted_mode, subreg_promoted_mode): New functions.
* expr.c (convert_move): Use them.
(convert_modes): Likewise.
(store_expr_with_bounds): Likewise.
diff --git a/gcc/expr.c b/gcc/expr.c
index 408a8bd..f682925 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -241,7 +241,7 @@ convert_move (rtx to, rtx from, int unsignedp)
if (GET_CODE (from) == SUBREG
&& SUBREG_PROMOTED_VAR_P (from)
&& is_a <scalar_int_mode> (to_mode, &to_int_mode)
- && (GET_MODE_PRECISION (GET_MODE (SUBREG_REG (from)))
+ && (GET_MODE_PRECISION (subreg_promoted_mode (from))
>= GET_MODE_PRECISION (to_int_mode))
&& SUBREG_CHECK_PROMOTED_SIGN (from, unsignedp))
from = gen_lowpart (to_int_mode, from), from_mode = to_int_mode;
@@ -639,7 +639,8 @@ convert_modes (machine_mode mode, machine_mode oldmode, rtx
x, int unsignedp)
if (GET_CODE (x) == SUBREG
&& SUBREG_PROMOTED_VAR_P (x)
&& is_a <scalar_int_mode> (mode, &int_mode)
- && GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))) >= GET_MODE_SIZE (int_mode)
+ && (GET_MODE_PRECISION (subreg_promoted_mode (x))
+ >= GET_MODE_PRECISION (int_mode))
&& SUBREG_CHECK_PROMOTED_SIGN (x, unsignedp))
x = gen_lowpart (int_mode, SUBREG_REG (x));
@@ -5414,6 +5415,8 @@ store_expr_with_bounds (tree exp, rtx target, int
call_param_p,
expression. */
{
rtx inner_target = 0;
+ scalar_int_mode outer_mode = subreg_unpromoted_mode (target);
+ scalar_int_mode inner_mode = subreg_promoted_mode (target);
/* We can do the conversion inside EXP, which will often result
in some optimizations. Do the conversion in two steps: first
@@ -5423,7 +5426,7 @@ store_expr_with_bounds (tree exp, rtx target, int
call_param_p,
converting modes. */
if (INTEGRAL_TYPE_P (TREE_TYPE (exp))
&& TREE_TYPE (TREE_TYPE (exp)) == 0
- && GET_MODE_PRECISION (GET_MODE (target))
+ && GET_MODE_PRECISION (outer_mode)
== TYPE_PRECISION (TREE_TYPE (exp)))
{
if (!SUBREG_CHECK_PROMOTED_SIGN (target,
@@ -5443,8 +5446,7 @@ store_expr_with_bounds (tree exp, rtx target, int
call_param_p,
}
exp = fold_convert_loc (loc, lang_hooks.types.type_for_mode
- (GET_MODE (SUBREG_REG (target)),
- SUBREG_PROMOTED_SIGN (target)),
+ (inner_mode, SUBREG_PROMOTED_SIGN (target)),
exp);
inner_target = SUBREG_REG (target);
@@ -5470,10 +5472,9 @@ store_expr_with_bounds (tree exp, rtx target, int
call_param_p,
sure that we properly convert it. */
if (CONSTANT_P (temp) && GET_MODE (temp) == VOIDmode)
{
- temp = convert_modes (GET_MODE (target), TYPE_MODE (TREE_TYPE (exp)),
+ temp = convert_modes (outer_mode, TYPE_MODE (TREE_TYPE (exp)),
temp, SUBREG_PROMOTED_SIGN (target));
- temp = convert_modes (GET_MODE (SUBREG_REG (target)),
- GET_MODE (target), temp,
+ temp = convert_modes (inner_mode, outer_mode, temp,
SUBREG_PROMOTED_SIGN (target));
}
diff --git a/gcc/rtl.h b/gcc/rtl.h
index 35f61c8..e65020a 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -2766,6 +2766,24 @@ unwrap_const_vec_duplicate (T x)
return x;
}
+/* Return the unpromoted (outer) mode of SUBREG_PROMOTED_VAR_P subreg X. */
+
+inline scalar_int_mode
+subreg_unpromoted_mode (rtx x)
+{
+ gcc_checking_assert (SUBREG_PROMOTED_VAR_P (x));
+ return as_a <scalar_int_mode> (GET_MODE (x));
+}
+
+/* Return the promoted (inner) mode of SUBREG_PROMOTED_VAR_P subreg X. */
+
+inline scalar_int_mode
+subreg_promoted_mode (rtx x)
+{
+ gcc_checking_assert (SUBREG_PROMOTED_VAR_P (x));
+ return as_a <scalar_int_mode> (GET_MODE (SUBREG_REG (x)));
+}
+
/* In emit-rtl.c */
extern rtvec gen_rtvec_v (int, rtx *);
extern rtvec gen_rtvec_v (int, rtx_insn **);
