From 077438933cf94f00cc5edf974338c11ba4bf7a39 Mon Sep 17 00:00:00 2001 From: Takayuki 'January June' Suwa Date: Tue, 14 Jun 2022 01:28:43 +0900 Subject: [PATCH] xtensa: Optimize bitwise AND operation with some specific forms of constants This patch offers several insn-and-split patterns for bitwise AND with register and constant that can be represented as: i. 1's least significant N bits and the others 0's (17 <= N <= 31) ii. 1's most significant N bits and the others 0's (12 <= N <= 31) iii. M 1's sequence of bits and trailing N 0's bits, that cannot fit into a "MOVI Ax, simm12" instruction (1 <= M <= 16, 1 <= N <= 30) And also offers shortcuts for conditional branch if each of the abovementioned operations is (not) equal to zero. gcc/ChangeLog: * config/xtensa/predicates.md (shifted_mask_operand): New predicate. * config/xtensa/xtensa.md (*andsi3_const_pow2_minus_one): New insn-and-split pattern. (*andsi3_const_negative_pow2, *andsi3_const_shifted_mask, *masktrue_const_pow2_minus_one, *masktrue_const_negative_pow2, *masktrue_const_shifted_mask): Ditto. --- gcc/config/xtensa/predicates.md | 10 +++ gcc/config/xtensa/xtensa.md | 179 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 189 insertions(+) diff --git a/gcc/config/xtensa/predicates.md b/gcc/config/xtensa/predicates.md index bcc83ad..d63a6cf 100644 --- a/gcc/config/xtensa/predicates.md +++ b/gcc/config/xtensa/predicates.md @@ -52,6 +52,16 @@ (match_test "xtensa_mask_immediate (INTVAL (op))")) (match_operand 0 "register_operand"))) +(define_predicate "shifted_mask_operand" + (match_code "const_int") +{ + HOST_WIDE_INT mask = INTVAL (op); + int shift = ctz_hwi (mask); + + return IN_RANGE (shift, 1, 31) + && xtensa_mask_immediate ((uint32_t)mask >> shift); +}) + (define_predicate "extui_fldsz_operand" (and (match_code "const_int") (match_test "IN_RANGE (INTVAL (op), 1, 16)"))) diff --git a/gcc/config/xtensa/xtensa.md b/gcc/config/xtensa/xtensa.md index a4477e2..5d0f346 100644 --- a/gcc/config/xtensa/xtensa.md +++ b/gcc/config/xtensa/xtensa.md @@ -645,6 +645,83 @@ (set_attr "mode" "SI") (set_attr "length" "6")]) +(define_insn_and_split "*andsi3_const_pow2_minus_one" + [(set (match_operand:SI 0 "register_operand" "=a") + (and:SI (match_operand:SI 1 "register_operand" "r") + (match_operand:SI 2 "const_int_operand" "i")))] + "IN_RANGE (exact_log2 (INTVAL (operands[2]) + 1), 17, 31)" + "#" + "&& 1" + [(set (match_dup 0) + (ashift:SI (match_dup 1) + (match_dup 2))) + (set (match_dup 0) + (lshiftrt:SI (match_dup 0) + (match_dup 2)))] +{ + operands[2] = GEN_INT (32 - floor_log2 (INTVAL (operands[2]) + 1)); +} + [(set_attr "type" "arith") + (set_attr "mode" "SI") + (set (attr "length") + (if_then_else (match_test "TARGET_DENSITY + && INTVAL (operands[2]) == 0x7FFFFFFF") + (const_int 5) + (const_int 6)))]) + +(define_insn_and_split "*andsi3_const_negative_pow2" + [(set (match_operand:SI 0 "register_operand" "=a") + (and:SI (match_operand:SI 1 "register_operand" "r") + (match_operand:SI 2 "const_int_operand" "i")))] + "IN_RANGE (exact_log2 (-INTVAL (operands[2])), 12, 31)" + "#" + "&& 1" + [(set (match_dup 0) + (lshiftrt:SI (match_dup 1) + (match_dup 2))) + (set (match_dup 0) + (ashift:SI (match_dup 0) + (match_dup 2)))] +{ + operands[2] = GEN_INT (floor_log2 (-INTVAL (operands[2]))); +} + [(set_attr "type" "arith") + (set_attr "mode" "SI") + (set_attr "length" "6")]) + +(define_insn_and_split "*andsi3_const_shifted_mask" + [(set (match_operand:SI 0 "register_operand" "=a") + (and:SI (match_operand:SI 1 "register_operand" "r") + (match_operand:SI 2 "shifted_mask_operand" "i")))] + "! xtensa_simm12b (INTVAL (operands[2]))" + "#" + "&& 1" + [(set (match_dup 0) + (zero_extract:SI (match_dup 1) + (match_dup 3) + (match_dup 4))) + (set (match_dup 0) + (ashift:SI (match_dup 0) + (match_dup 2)))] +{ + HOST_WIDE_INT mask = INTVAL (operands[2]); + int shift = ctz_hwi (mask); + int mask_size = floor_log2 (((uint32_t)mask >> shift) + 1); + int mask_pos = shift; + if (BITS_BIG_ENDIAN) + mask_pos = (32 - (mask_size + shift)) & 0x1f; + operands[2] = GEN_INT (shift); + operands[3] = GEN_INT (mask_size); + operands[4] = GEN_INT (mask_pos); +} + [(set_attr "type" "arith") + (set_attr "mode" "SI") + (set (attr "length") + (if_then_else (match_test "TARGET_DENSITY + && ctz_hwi (INTVAL (operands[2])) == 1") + (const_int 5) + (const_int 6)))]) + (define_insn "iorsi3" [(set (match_operand:SI 0 "register_operand" "=a") (ior:SI (match_operand:SI 1 "register_operand" "%r") @@ -1649,6 +1726,108 @@ (set_attr "mode" "none") (set_attr "length" "3")]) +(define_insn_and_split "*masktrue_const_pow2_minus_one" + [(set (pc) + (if_then_else (match_operator 3 "boolean_operator" + [(and:SI (match_operand:SI 0 "register_operand" "r") + (match_operand:SI 1 "const_int_operand" "i")) + (const_int 0)]) + (label_ref (match_operand 2 "" "")) + (pc)))] + "IN_RANGE (exact_log2 (INTVAL (operands[1]) + 1), 17, 31)" + "#" + "&& can_create_pseudo_p ()" + [(set (match_dup 4) + (ashift:SI (match_dup 0) + (match_dup 1))) + (set (pc) + (if_then_else (match_op_dup 3 + [(match_dup 4) + (const_int 0)]) + (label_ref (match_dup 2)) + (pc)))] +{ + operands[1] = GEN_INT (32 - floor_log2 (INTVAL (operands[1]) + 1)); + operands[4] = gen_reg_rtx (SImode); +} + [(set_attr "type" "jump") + (set_attr "mode" "none") + (set (attr "length") + (if_then_else (match_test "TARGET_DENSITY + && INTVAL (operands[1]) == 0x7FFFFFFF") + (const_int 5) + (const_int 6)))]) + +(define_insn_and_split "*masktrue_const_negative_pow2" + [(set (pc) + (if_then_else (match_operator 3 "boolean_operator" + [(and:SI (match_operand:SI 0 "register_operand" "r") + (match_operand:SI 1 "const_int_operand" "i")) + (const_int 0)]) + (label_ref (match_operand 2 "" "")) + (pc)))] + "IN_RANGE (exact_log2 (-INTVAL (operands[1])), 12, 30)" + "#" + "&& can_create_pseudo_p ()" + [(set (match_dup 4) + (lshiftrt:SI (match_dup 0) + (match_dup 1))) + (set (pc) + (if_then_else (match_op_dup 3 + [(match_dup 4) + (const_int 0)]) + (label_ref (match_dup 2)) + (pc)))] +{ + operands[1] = GEN_INT (floor_log2 (-INTVAL (operands[1]))); + operands[4] = gen_reg_rtx (SImode); +} + [(set_attr "type" "jump") + (set_attr "mode" "none") + (set_attr "length" "6")]) + +(define_insn_and_split "*masktrue_const_shifted_mask" + [(set (pc) + (if_then_else (match_operator 4 "boolean_operator" + [(and:SI (match_operand:SI 0 "register_operand" "r") + (match_operand:SI 1 "shifted_mask_operand" "i")) + (match_operand:SI 2 "const_int_operand" "i")]) + (label_ref (match_operand 3 "" "")) + (pc)))] + "(INTVAL (operands[2]) & ((1 << ctz_hwi (INTVAL (operands[1]))) - 1)) == 0 + && xtensa_b4const_or_zero ((uint32_t)INTVAL (operands[2]) >> ctz_hwi (INTVAL (operands[1])))" + "#" + "&& can_create_pseudo_p ()" + [(set (match_dup 6) + (zero_extract:SI (match_dup 0) + (match_dup 5) + (match_dup 1))) + (set (pc) + (if_then_else (match_op_dup 4 + [(match_dup 6) + (match_dup 2)]) + (label_ref (match_dup 3)) + (pc)))] +{ + HOST_WIDE_INT mask = INTVAL (operands[1]); + int shift = ctz_hwi (mask); + int mask_size = floor_log2 (((uint32_t)mask >> shift) + 1); + int mask_pos = shift; + if (BITS_BIG_ENDIAN) + mask_pos = (32 - (mask_size + shift)) & 0x1f; + operands[1] = GEN_INT (mask_pos); + operands[2] = GEN_INT ((uint32_t)INTVAL (operands[2]) >> shift); + operands[5] = GEN_INT (mask_size); + operands[6] = gen_reg_rtx (SImode); +} + [(set_attr "type" "jump") + (set_attr "mode" "none") + (set (attr "length") + (if_then_else (match_test "TARGET_DENSITY + && (uint32_t)INTVAL (operands[2]) >> ctz_hwi (INTVAL (operands[1])) == 0") + (const_int 5) + (const_int 6)))]) + ;; Zero-overhead looping support. -- 2.7.4