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//===-- RISCVInstrInfoM.td - RISC-V 'M' instructions -------*- tablegen -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file describes the RISC-V instructions from the standard 'M', Integer
// Multiplication and Division instruction set extension.
//
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
// RISC-V specific DAG Nodes.
//===----------------------------------------------------------------------===//
def riscv_mulhsu : SDNode<"RISCVISD::MULHSU", SDTIntBinOp>;
def riscv_divw : SDNode<"RISCVISD::DIVW", SDT_RISCVIntBinOpW>;
def riscv_divuw : SDNode<"RISCVISD::DIVUW", SDT_RISCVIntBinOpW>;
def riscv_remuw : SDNode<"RISCVISD::REMUW", SDT_RISCVIntBinOpW>;
//===----------------------------------------------------------------------===//
// Instructions
//===----------------------------------------------------------------------===//
let Predicates = [HasStdExtM] in {
def MUL : ALU_rr<0b0000001, 0b000, "mul">,
Sched<[WriteIMul, ReadIMul, ReadIMul]>;
def MULH : ALU_rr<0b0000001, 0b001, "mulh">,
Sched<[WriteIMul, ReadIMul, ReadIMul]>;
def MULHSU : ALU_rr<0b0000001, 0b010, "mulhsu">,
Sched<[WriteIMul, ReadIMul, ReadIMul]>;
def MULHU : ALU_rr<0b0000001, 0b011, "mulhu">,
Sched<[WriteIMul, ReadIMul, ReadIMul]>;
def DIV : ALU_rr<0b0000001, 0b100, "div">,
Sched<[WriteIDiv, ReadIDiv, ReadIDiv]>;
def DIVU : ALU_rr<0b0000001, 0b101, "divu">,
Sched<[WriteIDiv, ReadIDiv, ReadIDiv]>;
def REM : ALU_rr<0b0000001, 0b110, "rem">,
Sched<[WriteIDiv, ReadIDiv, ReadIDiv]>;
def REMU : ALU_rr<0b0000001, 0b111, "remu">,
Sched<[WriteIDiv, ReadIDiv, ReadIDiv]>;
} // Predicates = [HasStdExtM]
let Predicates = [HasStdExtM, IsRV64] in {
def MULW : ALUW_rr<0b0000001, 0b000, "mulw">,
Sched<[WriteIMul32, ReadIMul32, ReadIMul32]>;
def DIVW : ALUW_rr<0b0000001, 0b100, "divw">,
Sched<[WriteIDiv32, ReadIDiv32, ReadIDiv32]>;
def DIVUW : ALUW_rr<0b0000001, 0b101, "divuw">,
Sched<[WriteIDiv32, ReadIDiv32, ReadIDiv32]>;
def REMW : ALUW_rr<0b0000001, 0b110, "remw">,
Sched<[WriteIDiv32, ReadIDiv32, ReadIDiv32]>;
def REMUW : ALUW_rr<0b0000001, 0b111, "remuw">,
Sched<[WriteIDiv32, ReadIDiv32, ReadIDiv32]>;
} // Predicates = [HasStdExtM, IsRV64]
//===----------------------------------------------------------------------===//
// Pseudo-instructions and codegen patterns
//===----------------------------------------------------------------------===//
let Predicates = [HasStdExtM] in {
def : PatGprGpr<mul, MUL>;
def : PatGprGpr<mulhs, MULH>;
def : PatGprGpr<mulhu, MULHU>;
def : PatGprGpr<riscv_mulhsu, MULHSU>;
def : PatGprGpr<sdiv, DIV>;
def : PatGprGpr<udiv, DIVU>;
def : PatGprGpr<srem, REM>;
def : PatGprGpr<urem, REMU>;
} // Predicates = [HasStdExtM]
let Predicates = [HasStdExtM, IsRV64] in {
def : Pat<(sext_inreg (mul GPR:$rs1, GPR:$rs2), i32),
(MULW GPR:$rs1, GPR:$rs2)>;
def : PatGprGpr<riscv_divw, DIVW>;
def : PatGprGpr<riscv_divuw, DIVUW>;
def : PatGprGpr<riscv_remuw, REMUW>;
// Handle the specific cases where using DIVU/REMU would be correct and result
// in fewer instructions than emitting DIVUW/REMUW then zero-extending the
// result.
def : Pat<(and (riscv_divuw (assertzexti32 GPR:$rs1),
(assertzexti32 GPR:$rs2)), 0xffffffff),
(DIVU GPR:$rs1, GPR:$rs2)>;
def : Pat<(and (riscv_remuw (assertzexti32 GPR:$rs1),
(assertzexti32 GPR:$rs2)), 0xffffffff),
(REMU GPR:$rs1, GPR:$rs2)>;
// Although the sexti32 operands may not have originated from an i32 srem,
// this pattern is safe as it is impossible for two sign extended inputs to
// produce a result where res[63:32]=0 and res[31]=1.
def : Pat<(srem (sexti32 (i64 GPR:$rs1)), (sexti32 (i64 GPR:$rs2))),
(REMW GPR:$rs1, GPR:$rs2)>;
} // Predicates = [HasStdExtM, IsRV64]
let Predicates = [HasStdExtM, IsRV64, NotHasStdExtZba] in {
// Special case for calculating the full 64-bit product of a 32x32 unsigned
// multiply where the inputs aren't known to be zero extended. We can shift the
// inputs left by 32 and use a MULHU. This saves two SRLIs needed to finish
// zeroing the upper 32 bits.
// TODO: If one of the operands is zero extended and the other isn't, we might
// still be better off shifting both left by 32.
def : Pat<(i64 (mul (and GPR:$rs1, 0xffffffff), (and GPR:$rs2, 0xffffffff))),
(MULHU (SLLI GPR:$rs1, 32), (SLLI GPR:$rs2, 32))>;
// Prevent matching the first part of this pattern to mulw. The mul here has
// additionals users or the ANDs would have been removed. The above pattern
// will be used for the other users. If we form a mulw we'll keep the ANDs alive
// and they'll still become SLLI+SRLI.
def : Pat<(sext_inreg (mul (and GPR:$rs1, 0xffffffff),
(and GPR:$rs2, 0xffffffff)), i32),
(ADDIW (MULHU (SLLI GPR:$rs1, 32), (SLLI GPR:$rs2, 32)), 0)>;
} // Predicates = [HasStdExtM, IsRV64, NotHasStdExtZba]
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