This patch adds early expansion of usubvdi4, allowing us to handle some
constants in place, which previously we were unable to do.
* config/arm/arm.md (usubvdi4): Allow registers or integers for
incoming operands. Early split the calculation into SImode
operations.
(usubvsi3_borrow): New insn pattern.
(usubvsi3_borrow_imm): Likewise.
---
gcc/config/arm/arm.md | 113 ++++++++++++++++++++++++++++++++++++++++--
1 file changed, 109 insertions(+), 4 deletions(-)
diff --git a/gcc/config/arm/arm.md b/gcc/config/arm/arm.md
index a465bf8e7a3..92f1823cdfa 100644
--- a/gcc/config/arm/arm.md
+++ b/gcc/config/arm/arm.md
@@ -1390,13 +1390,81 @@ (define_expand "usubvsi4"
(define_expand "usubvdi4"
[(match_operand:DI 0 "s_register_operand")
- (match_operand:DI 1 "s_register_operand")
- (match_operand:DI 2 "s_register_operand")
+ (match_operand:DI 1 "reg_or_int_operand")
+ (match_operand:DI 2 "reg_or_int_operand")
(match_operand 3 "")]
"TARGET_32BIT"
{
- emit_insn (gen_subdi3_compare1 (operands[0], operands[1], operands[2]));
- arm_gen_unlikely_cbranch (LTU, CCmode, operands[3]);
+ rtx lo_result, hi_result;
+ rtx lo_op1, hi_op1, lo_op2, hi_op2;
+ lo_result = gen_lowpart (SImode, operands[0]);
+ hi_result = gen_highpart (SImode, operands[0]);
+ machine_mode mode = CCmode;
+
+ if (CONST_INT_P (operands[1]) && CONST_INT_P (operands[2]))
+ {
+ /* If both operands are constants we can decide the result statically. */
+ wi::overflow_type overflow;
+ wide_int val = wi::sub (rtx_mode_t (operands[1], DImode),
+ rtx_mode_t (operands[2], DImode),
+ UNSIGNED, &overflow);
+ emit_move_insn (operands[0], GEN_INT (val.to_shwi ()));
+ if (overflow != wi::OVF_NONE)
+ emit_jump_insn (gen_jump (operands[3]));
+ DONE;
+ }
+ else if (CONST_INT_P (operands[1]))
+ {
+ arm_decompose_di_binop (operands[2], operands[1], &lo_op2, &hi_op2,
+ &lo_op1, &hi_op1);
+ if (const_ok_for_arm (INTVAL (lo_op1)))
+ {
+ emit_insn (gen_rsb_imm_compare (lo_result, lo_op1, lo_op2,
+ GEN_INT (~UINTVAL (lo_op1))));
+ /* We could potentially use RSC here in Arm state, but not
+ in Thumb, so it's probably not worth the effort of handling
+ this. */
+ hi_op1 = force_reg (SImode, hi_op1);
+ mode = CC_RSBmode;
+ goto highpart;
+ }
+ operands[1] = force_reg (DImode, operands[1]);
+ }
+
+ arm_decompose_di_binop (operands[1], operands[2], &lo_op1, &hi_op1,
+ &lo_op2, &hi_op2);
+ if (lo_op2 == const0_rtx)
+ {
+ emit_move_insn (lo_result, lo_op1);
+ if (!arm_add_operand (hi_op2, SImode))
+ hi_op2 = force_reg (SImode, hi_op2);
+ emit_insn (gen_usubvsi4 (hi_result, hi_op1, hi_op2, operands[3]));
+ DONE;
+ }
+
+ if (CONST_INT_P (lo_op2) && !arm_addimm_operand (lo_op2, SImode))
+ lo_op2 = force_reg (SImode, lo_op2);
+ if (CONST_INT_P (lo_op2))
+ emit_insn (gen_cmpsi2_addneg (lo_result, lo_op1, lo_op2,
+ GEN_INT (-INTVAL (lo_op2))));
+ else
+ emit_insn (gen_subsi3_compare1 (lo_result, lo_op1, lo_op2));
+
+ highpart:
+ if (!arm_not_operand (hi_op2, SImode))
+ hi_op2 = force_reg (SImode, hi_op2);
+ rtx ccreg = gen_rtx_REG (mode, CC_REGNUM);
+ if (CONST_INT_P (hi_op2))
+ emit_insn (gen_usubvsi3_borrow_imm (hi_result, hi_op1, hi_op2,
+ GEN_INT (UINTVAL (hi_op2) & 0xffffffff),
+ gen_rtx_LTU (SImode, ccreg, const0_rtx),
+ gen_rtx_LTU (DImode, ccreg,
+ const0_rtx)));
+ else
+ emit_insn (gen_usubvsi3_borrow (hi_result, hi_op1, hi_op2,
+ gen_rtx_LTU (SImode, ccreg, const0_rtx),
+ gen_rtx_LTU (DImode, ccreg, const0_rtx)));
+ arm_gen_unlikely_cbranch (LTU, CC_Bmode, operands[3]);
DONE;
})
@@ -1825,6 +1893,43 @@ (define_insn "rscsi3_<CC_EXTEND>out_scratch"
(set_attr "type" "alus_imm")]
)
+(define_insn "usubvsi3_borrow"
+ [(set (reg:CC_B CC_REGNUM)
+ (compare:CC_B
+ (zero_extend:DI (match_operand:SI 1 "s_register_operand" "0,r"))
+ (plus:DI (match_operand:DI 4 "arm_borrow_operation" "")
+ (zero_extend:DI
+ (match_operand:SI 2 "s_register_operand" "l,r")))))
+ (set (match_operand:SI 0 "s_register_operand" "=l,r")
+ (minus:SI (match_dup 1)
+ (plus:SI (match_operand:SI 3 "arm_borrow_operation" "")
+ (match_dup 2))))]
+ "TARGET_32BIT"
+ "sbcs%?\\t%0, %1, %2"
+ [(set_attr "conds" "set")
+ (set_attr "arch" "t2,*")
+ (set_attr "length" "2,4")]
+)
+
+(define_insn "usubvsi3_borrow_imm"
+ [(set (reg:CC_B CC_REGNUM)
+ (compare:CC_B
+ (zero_extend:DI (match_operand:SI 1 "s_register_operand" "r,r"))
+ (plus:DI (match_operand:DI 5 "arm_borrow_operation" "")
+ (match_operand:DI 3 "const_int_operand" "n,n"))))
+ (set (match_operand:SI 0 "s_register_operand" "=r,r")
+ (minus:SI (match_dup 1)
+ (plus:SI (match_operand:SI 4 "arm_borrow_operation" "")
+ (match_operand:SI 2 "arm_adcimm_operand" "I,K"))))]
+ "TARGET_32BIT
+ && (UINTVAL (operands[2]) & 0xffffffff) == UINTVAL (operands[3])"
+ "@
+ sbcs%?\\t%0, %1, %2
+ adcs%?\\t%0, %1, #%B2"
+ [(set_attr "conds" "set")
+ (set_attr "type" "alus_imm")]
+)
+
(define_expand "subsf3"
[(set (match_operand:SF 0 "s_register_operand")
(minus:SF (match_operand:SF 1 "s_register_operand")
