[gcc r14-1836] i386: Add peephole2 patterns to improve subtract with borrow with memory destination [PR79173]
Jakub Jelinek
jakub@gcc.gnu.org
Thu Jun 15 07:10:26 GMT 2023
https://gcc.gnu.org/g:ec52d228d6db7f77188ad099a8c0ff65dead3241
commit r14-1836-gec52d228d6db7f77188ad099a8c0ff65dead3241
Author: Jakub Jelinek <jakub@redhat.com>
Date: Thu Jun 15 09:08:37 2023 +0200
i386: Add peephole2 patterns to improve subtract with borrow with memory destination [PR79173]
This patch adds subborrow<mode> alternative so that it can have memory
destination and adds various peephole2s which help to match it.
2023-06-15 Jakub Jelinek <jakub@redhat.com>
PR middle-end/79173
* config/i386/i386.md (subborrow<mode>): Add alternative with
memory destination and add for it define_peephole2
TARGET_READ_MODIFY_WRITE/-Os patterns to prefer using memory
destination in these patterns.
Diff:
---
gcc/config/i386/i386.md | 154 +++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 151 insertions(+), 3 deletions(-)
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 23be04f5218..75eda25dfcd 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -8381,13 +8381,13 @@
[(set (reg:CCC FLAGS_REG)
(compare:CCC
(zero_extend:<DWI>
- (match_operand:SWI48 1 "nonimmediate_operand" "0"))
+ (match_operand:SWI48 1 "nonimmediate_operand" "0,0"))
(plus:<DWI>
(match_operator:<DWI> 4 "ix86_carry_flag_operator"
[(match_operand 3 "flags_reg_operand") (const_int 0)])
(zero_extend:<DWI>
- (match_operand:SWI48 2 "nonimmediate_operand" "rm")))))
- (set (match_operand:SWI48 0 "register_operand" "=r")
+ (match_operand:SWI48 2 "nonimmediate_operand" "r,rm")))))
+ (set (match_operand:SWI48 0 "nonimmediate_operand" "=rm,r")
(minus:SWI48 (minus:SWI48
(match_dup 1)
(match_operator:SWI48 5 "ix86_carry_flag_operator"
@@ -8400,6 +8400,154 @@
(set_attr "pent_pair" "pu")
(set_attr "mode" "<MODE>")])
+(define_peephole2
+ [(set (match_operand:SWI48 0 "general_reg_operand")
+ (match_operand:SWI48 1 "memory_operand"))
+ (parallel [(set (reg:CCC FLAGS_REG)
+ (compare:CCC
+ (zero_extend:<DWI> (match_dup 0))
+ (plus:<DWI>
+ (match_operator:<DWI> 4 "ix86_carry_flag_operator"
+ [(match_operand 3 "flags_reg_operand") (const_int 0)])
+ (zero_extend:<DWI>
+ (match_operand:SWI48 2 "memory_operand")))))
+ (set (match_dup 0)
+ (minus:SWI48
+ (minus:SWI48
+ (match_dup 0)
+ (match_operator:SWI48 5 "ix86_carry_flag_operator"
+ [(match_dup 3) (const_int 0)]))
+ (match_dup 2)))])
+ (set (match_dup 1) (match_dup 0))]
+ "(TARGET_READ_MODIFY_WRITE || optimize_insn_for_size_p ())
+ && peep2_reg_dead_p (3, operands[0])
+ && !reg_overlap_mentioned_p (operands[0], operands[1])
+ && !reg_overlap_mentioned_p (operands[0], operands[2])"
+ [(set (match_dup 0) (match_dup 2))
+ (parallel [(set (reg:CCC FLAGS_REG)
+ (compare:CCC
+ (zero_extend:<DWI> (match_dup 1))
+ (plus:<DWI> (match_op_dup 4
+ [(match_dup 3) (const_int 0)])
+ (zero_extend:<DWI> (match_dup 0)))))
+ (set (match_dup 1)
+ (minus:SWI48 (minus:SWI48 (match_dup 1)
+ (match_op_dup 5
+ [(match_dup 3) (const_int 0)]))
+ (match_dup 0)))])])
+
+(define_peephole2
+ [(set (match_operand:SWI48 6 "general_reg_operand")
+ (match_operand:SWI48 7 "memory_operand"))
+ (set (match_operand:SWI48 8 "general_reg_operand")
+ (match_operand:SWI48 9 "memory_operand"))
+ (parallel [(set (reg:CCC FLAGS_REG)
+ (compare:CCC
+ (zero_extend:<DWI>
+ (match_operand:SWI48 0 "general_reg_operand"))
+ (plus:<DWI>
+ (match_operator:<DWI> 4 "ix86_carry_flag_operator"
+ [(match_operand 3 "flags_reg_operand") (const_int 0)])
+ (zero_extend:<DWI>
+ (match_operand:SWI48 2 "general_reg_operand")))))
+ (set (match_dup 0)
+ (minus:SWI48
+ (minus:SWI48
+ (match_dup 0)
+ (match_operator:SWI48 5 "ix86_carry_flag_operator"
+ [(match_dup 3) (const_int 0)]))
+ (match_dup 2)))])
+ (set (match_operand:SWI48 1 "memory_operand") (match_dup 0))]
+ "(TARGET_READ_MODIFY_WRITE || optimize_insn_for_size_p ())
+ && peep2_reg_dead_p (4, operands[0])
+ && peep2_reg_dead_p (3, operands[2])
+ && !reg_overlap_mentioned_p (operands[0], operands[1])
+ && !reg_overlap_mentioned_p (operands[2], operands[1])
+ && !reg_overlap_mentioned_p (operands[6], operands[9])
+ && (rtx_equal_p (operands[6], operands[0])
+ ? (rtx_equal_p (operands[7], operands[1])
+ && rtx_equal_p (operands[8], operands[2]))
+ : (rtx_equal_p (operands[8], operands[0])
+ && rtx_equal_p (operands[9], operands[1])
+ && rtx_equal_p (operands[6], operands[2])))"
+ [(set (match_dup 0) (match_dup 9))
+ (parallel [(set (reg:CCC FLAGS_REG)
+ (compare:CCC
+ (zero_extend:<DWI> (match_dup 1))
+ (plus:<DWI> (match_op_dup 4
+ [(match_dup 3) (const_int 0)])
+ (zero_extend:<DWI> (match_dup 0)))))
+ (set (match_dup 1)
+ (minus:SWI48 (minus:SWI48 (match_dup 1)
+ (match_op_dup 5
+ [(match_dup 3) (const_int 0)]))
+ (match_dup 0)))])]
+{
+ if (!rtx_equal_p (operands[6], operands[0]))
+ operands[9] = operands[7];
+})
+
+(define_peephole2
+ [(set (match_operand:SWI48 6 "general_reg_operand")
+ (match_operand:SWI48 7 "memory_operand"))
+ (set (match_operand:SWI48 8 "general_reg_operand")
+ (match_operand:SWI48 9 "memory_operand"))
+ (parallel [(set (reg:CCC FLAGS_REG)
+ (compare:CCC
+ (zero_extend:<DWI>
+ (match_operand:SWI48 0 "general_reg_operand"))
+ (plus:<DWI>
+ (match_operator:<DWI> 4 "ix86_carry_flag_operator"
+ [(match_operand 3 "flags_reg_operand") (const_int 0)])
+ (zero_extend:<DWI>
+ (match_operand:SWI48 2 "general_reg_operand")))))
+ (set (match_dup 0)
+ (minus:SWI48
+ (minus:SWI48
+ (match_dup 0)
+ (match_operator:SWI48 5 "ix86_carry_flag_operator"
+ [(match_dup 3) (const_int 0)]))
+ (match_dup 2)))])
+ (set (match_operand:QI 10 "general_reg_operand")
+ (ltu:QI (reg:CCC FLAGS_REG) (const_int 0)))
+ (set (match_operand:SWI48 11 "general_reg_operand")
+ (zero_extend:SWI48 (match_dup 10)))
+ (set (match_operand:SWI48 1 "memory_operand") (match_dup 0))]
+ "(TARGET_READ_MODIFY_WRITE || optimize_insn_for_size_p ())
+ && peep2_reg_dead_p (6, operands[0])
+ && peep2_reg_dead_p (3, operands[2])
+ && !reg_overlap_mentioned_p (operands[0], operands[1])
+ && !reg_overlap_mentioned_p (operands[2], operands[1])
+ && !reg_overlap_mentioned_p (operands[6], operands[9])
+ && !reg_overlap_mentioned_p (operands[0], operands[10])
+ && !reg_overlap_mentioned_p (operands[10], operands[1])
+ && !reg_overlap_mentioned_p (operands[0], operands[11])
+ && !reg_overlap_mentioned_p (operands[11], operands[1])
+ && (rtx_equal_p (operands[6], operands[0])
+ ? (rtx_equal_p (operands[7], operands[1])
+ && rtx_equal_p (operands[8], operands[2]))
+ : (rtx_equal_p (operands[8], operands[0])
+ && rtx_equal_p (operands[9], operands[1])
+ && rtx_equal_p (operands[6], operands[2])))"
+ [(set (match_dup 0) (match_dup 9))
+ (parallel [(set (reg:CCC FLAGS_REG)
+ (compare:CCC
+ (zero_extend:<DWI> (match_dup 1))
+ (plus:<DWI> (match_op_dup 4
+ [(match_dup 3) (const_int 0)])
+ (zero_extend:<DWI> (match_dup 0)))))
+ (set (match_dup 1)
+ (minus:SWI48 (minus:SWI48 (match_dup 1)
+ (match_op_dup 5
+ [(match_dup 3) (const_int 0)]))
+ (match_dup 0)))])
+ (set (match_dup 10) (ltu:QI (reg:CCC FLAGS_REG) (const_int 0)))
+ (set (match_dup 11) (zero_extend:SWI48 (match_dup 10)))]
+{
+ if (!rtx_equal_p (operands[6], operands[0]))
+ operands[9] = operands[7];
+})
+
(define_expand "subborrow<mode>_0"
[(parallel
[(set (reg:CC FLAGS_REG)
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