This patch adds basic support for the Thumb ADDW and SUBW instructions.
The patch permits the compiler to use the new instructions for constants
that can be loaded with a single instruction (i.e. 16-bit unshifted),
but does not support use of addw with split-constants; I have a patch
for that coming soon.
This patch requires that my previously posted patch for MOVW is applied
first.
OK?
Andrew
2011-04-20 Andrew Stubbs <a...@codesourcery.com>
gcc/
* config/arm/arm-protos.h (const_ok_for_op): Add prototype.
* config/arm/arm.c (const_ok_for_op): Add support for addw/subw.
Remove prototype. Remove static function type.
* config/arm/arm.md (*arm_addsi3): Add addw/subw support.
Add arch attribute.
(*arm_subsi3_insn): Add subw support.
Add arch attribute.
* config/arm/constraints.md (Pj, PJ): New constraints.
--- a/gcc/config/arm/arm-protos.h
+++ b/gcc/config/arm/arm-protos.h
@@ -46,6 +46,7 @@ extern bool arm_vector_mode_supported_p (enum machine_mode);
extern bool arm_small_register_classes_for_mode_p (enum machine_mode);
extern int arm_hard_regno_mode_ok (unsigned int, enum machine_mode);
extern int const_ok_for_arm (HOST_WIDE_INT);
+extern int const_ok_for_op (HOST_WIDE_INT, enum rtx_code);
extern int arm_split_constant (RTX_CODE, enum machine_mode, rtx,
HOST_WIDE_INT, rtx, rtx, int);
extern RTX_CODE arm_canonicalize_comparison (RTX_CODE, rtx *, rtx *);
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -82,7 +82,6 @@ inline static int thumb1_index_register_rtx_p (rtx, int);
static bool arm_legitimate_address_p (enum machine_mode, rtx, bool);
static int thumb_far_jump_used_p (void);
static bool thumb_force_lr_save (void);
-static int const_ok_for_op (HOST_WIDE_INT, enum rtx_code);
static rtx emit_sfm (int, int);
static unsigned arm_size_return_regs (void);
static bool arm_assemble_integer (rtx, unsigned int, int);
@@ -2453,7 +2452,7 @@ const_ok_for_arm (HOST_WIDE_INT i)
}
/* Return true if I is a valid constant for the operation CODE. */
-static int
+int
const_ok_for_op (HOST_WIDE_INT i, enum rtx_code code)
{
if (const_ok_for_arm (i))
@@ -2469,6 +2468,13 @@ const_ok_for_op (HOST_WIDE_INT i, enum rtx_code code)
return 0;
case PLUS:
+ /* See if we can use addw or subw. */
+ if (TARGET_THUMB2
+ && ((i & 0xfffff000) == 0
+ || ((-i) & 0xfffff000) == 0))
+ return 1;
+ /* else fall through. */
+
case COMPARE:
case EQ:
case NE:
--- a/gcc/config/arm/arm.md
+++ b/gcc/config/arm/arm.md
@@ -707,21 +707,24 @@
;; (plus (reg rN) (reg sp)) into (reg rN). In this case reload will
;; put the duplicated register first, and not try the commutative version.
(define_insn_and_split "*arm_addsi3"
- [(set (match_operand:SI 0 "s_register_operand" "=r, k,r,r, k,r")
- (plus:SI (match_operand:SI 1 "s_register_operand" "%rk,k,r,rk,k,rk")
- (match_operand:SI 2 "reg_or_int_operand" "rI,rI,k,L, L,?n")))]
+ [(set (match_operand:SI 0 "s_register_operand" "=r, k,r,r, k, r, k,r, k, r")
+ (plus:SI (match_operand:SI 1 "s_register_operand" "%rk,k,r,rk,k, rk,k,rk,k, rk")
+ (match_operand:SI 2 "reg_or_int_operand" "rI,rI,k,Pj,Pj,L, L,PJ,PJ,?n")))]
"TARGET_32BIT"
"@
add%?\\t%0, %1, %2
add%?\\t%0, %1, %2
add%?\\t%0, %2, %1
+ addw%?\\t%0, %1, %2
+ addw%?\\t%0, %1, %2
sub%?\\t%0, %1, #%n2
sub%?\\t%0, %1, #%n2
+ subw%?\\t%0, %1, #%n2
+ subw%?\\t%0, %1, #%n2
#"
"TARGET_32BIT
&& GET_CODE (operands[2]) == CONST_INT
- && !(const_ok_for_arm (INTVAL (operands[2]))
- || const_ok_for_arm (-INTVAL (operands[2])))
+ && !const_ok_for_op (INTVAL (operands[2]), PLUS)
&& (reload_completed || !arm_eliminable_register (operands[1]))"
[(clobber (const_int 0))]
"
@@ -730,8 +733,9 @@
operands[1], 0);
DONE;
"
- [(set_attr "length" "4,4,4,4,4,16")
- (set_attr "predicable" "yes")]
+ [(set_attr "length" "4,4,4,4,4,4,4,4,4,16")
+ (set_attr "predicable" "yes")
+ (set_attr "arch" "*,*,*,t2,t2,*,*,t2,t2,*")]
)
(define_insn_and_split "*thumb1_addsi3"
@@ -1184,28 +1188,33 @@
; ??? Check Thumb-2 split length
(define_insn_and_split "*arm_subsi3_insn"
- [(set (match_operand:SI 0 "s_register_operand" "=r,r,rk,r,r")
- (minus:SI (match_operand:SI 1 "reg_or_int_operand" "rI,r,k,?n,r")
- (match_operand:SI 2 "reg_or_int_operand" "r,rI,r, r,?n")))]
+ [(set (match_operand:SI 0 "s_register_operand" "=r,r,rk,r, k, r,r")
+ (minus:SI (match_operand:SI 1 "reg_or_int_operand" "rI,r,k, rk,k, ?n,r")
+ (match_operand:SI 2 "reg_or_int_operand" "r,rI,r, Pj,Pj,r,?n")))]
"TARGET_32BIT"
"@
rsb%?\\t%0, %2, %1
sub%?\\t%0, %1, %2
sub%?\\t%0, %1, %2
+ subw%?\\t%0, %1, %2
+ subw%?\\t%0, %1, %2
#
#"
"&& ((GET_CODE (operands[1]) == CONST_INT
- && !const_ok_for_arm (INTVAL (operands[1])))
+ && !(const_ok_for_arm (INTVAL (operands[1]))
+ || satisfies_constraint_Pj (operands[2])))
|| (GET_CODE (operands[2]) == CONST_INT
- && !const_ok_for_arm (INTVAL (operands[2]))))"
+ && !(const_ok_for_arm (INTVAL (operands[2]))
+ || satisfies_constraint_Pj (operands[2]))))"
[(clobber (const_int 0))]
"
arm_split_constant (MINUS, SImode, curr_insn,
INTVAL (operands[1]), operands[0], operands[2], 0);
DONE;
"
- [(set_attr "length" "4,4,4,16,16")
- (set_attr "predicable" "yes")]
+ [(set_attr "length" "4,4,4,4,4,16,16")
+ (set_attr "predicable" "yes")
+ (set_attr "arch" "*,*,*,t2,t2,*,*")]
)
(define_peephole2
--- a/gcc/config/arm/constraints.md
+++ b/gcc/config/arm/constraints.md
@@ -31,7 +31,7 @@
;; The following multi-letter normal constraints have been used:
;; in ARM/Thumb-2 state: Da, Db, Dc, Dn, Dl, DL, Dv, Dy, Di, Dz
;; in Thumb-1 state: Pa, Pb, Pc, Pd
-;; in Thumb-2 state: Ps, Pt, Pu, Pv, Pw, Px, Py
+;; in Thumb-2 state: Pj, PJ, Ps, Pt, Pu, Pv, Pw, Px, Py
;; The following memory constraints have been used:
;; in ARM/Thumb-2 state: Q, Ut, Uv, Uy, Un, Um, Us
@@ -74,6 +74,18 @@
(and (match_code "const_int")
(match_test "(ival & 0xffff0000) == 0")))))
+(define_constraint "Pj"
+ "A 12-bit constant suitable for an ADDW or SUBW instruction. (Thumb-2)"
+ (and (match_code "const_int")
+ (and (match_test "TARGET_THUMB2")
+ (match_test "(ival & 0xfffff000) == 0"))))
+
+(define_constraint "PJ"
+ "A constant that satisfies the Pj constrant if negated."
+ (and (match_code "const_int")
+ (and (match_test "TARGET_THUMB2")
+ (match_test "((-ival) & 0xfffff000) == 0"))))
+
(define_register_constraint "k" "STACK_REG"
"@internal The stack register.")
