From bb65bd084a8739feb5b85f87135c531fc8b86572 Mon Sep 17 00:00:00 2001 From: Takayuki 'January June' Suwa Date: Thu, 12 Jan 2023 13:25:58 +0900 Subject: [PATCH] xtensa: Tune "*btrue" insn pattern This branch instruction has short encoding if EQ/NE comparison against immediate zero when the Code Density Option is enabled, but its "length" attribute was only for normal encoding. This patch fixes it. This patch also prevents undesireable replacement the comparison immediate zero of the instruction (short encoding, as mentioned above) with a register that has value of zero (normal encoding) by the postreload pass. gcc/ChangeLog: * config/xtensa/xtensa.md (*btrue): Correct value of the attribute "length" that depends on TARGET_DENSITY and operands, and add '?' character to the register constraint of the compared operand. --- gcc/config/xtensa/xtensa.md | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/gcc/config/xtensa/xtensa.md b/gcc/config/xtensa/xtensa.md index db1d68e..b498983 100644 --- a/gcc/config/xtensa/xtensa.md +++ b/gcc/config/xtensa/xtensa.md @@ -1679,7 +1679,7 @@ [(set (pc) (if_then_else (match_operator 3 "branch_operator" [(match_operand:SI 0 "register_operand" "r,r") - (match_operand:SI 1 "branch_operand" "K,r")]) + (match_operand:SI 1 "branch_operand" "K,?r")]) (label_ref (match_operand 2 "" "")) (pc)))] "" @@ -1688,7 +1688,14 @@ } [(set_attr "type" "jump,jump") (set_attr "mode" "none") - (set_attr "length" "3,3")]) + (set (attr "length") + (if_then_else (match_test "TARGET_DENSITY + && CONST_INT_P (operands[1]) + && INTVAL (operands[1]) == 0 + && (GET_CODE (operands[3]) == EQ + || GET_CODE (operands[3]) == NE)") + (const_int 2) + (const_int 3)))]) (define_insn "*ubtrue" [(set (pc) -- 2.7.4