llvm-6502/lib/Target/SystemZ/SystemZPatterns.td
Richard Sandiford aff1c6427c [SystemZ] Tweak integer comparison code
The architecture has many comparison instructions, including some that
extend one of the operands.  The signed comparison instructions use sign
extensions and the unsigned comparison instructions use zero extensions.
In cases where we had a free choice between signed or unsigned comparisons,
we were trying to decide at lowering time which would best fit the available
instructions, taking things like extension type into account.  The code
to do that was getting increasingly hairy and was also making some bad
decisions.  E.g. when comparing the result of two LLCs, it is better to use
CR rather than CLR, since CR can be fused with a branch while CLR can't.

This patch removes the lowering code and instead adds an operand to
integer comparisons to say whether signed comparison is required,
whether unsigned comparison is required, or whether either is OK.
We can then leave the choice of instruction up to the normal isel code.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190138 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-06 11:51:39 +00:00

107 lines
5.0 KiB
TableGen

//===-- SystemZPatterns.td - SystemZ-specific pattern rules ---*- tblgen-*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// Record that INSN performs a 64-bit version of unary operator OPERATOR
// in which the operand is sign-extended from 32 to 64 bits.
multiclass SXU<SDPatternOperator operator, Instruction insn> {
def : Pat<(operator (sext (i32 GR32:$src))),
(insn GR32:$src)>;
def : Pat<(operator (sext_inreg GR64:$src, i32)),
(insn (EXTRACT_SUBREG GR64:$src, subreg_32bit))>;
}
// Record that INSN performs a 64-bit version of binary operator OPERATOR
// in which the first operand has class CLS and which the second operand
// is sign-extended from a 32-bit register.
multiclass SXB<SDPatternOperator operator, RegisterOperand cls,
Instruction insn> {
def : Pat<(operator cls:$src1, (sext GR32:$src2)),
(insn cls:$src1, GR32:$src2)>;
def : Pat<(operator cls:$src1, (sext_inreg GR64:$src2, i32)),
(insn cls:$src1, (EXTRACT_SUBREG GR64:$src2, subreg_32bit))>;
}
// Like SXB, but for zero extension.
multiclass ZXB<SDPatternOperator operator, RegisterOperand cls,
Instruction insn> {
def : Pat<(operator cls:$src1, (zext GR32:$src2)),
(insn cls:$src1, GR32:$src2)>;
def : Pat<(operator cls:$src1, (and GR64:$src2, 0xffffffff)),
(insn cls:$src1, (EXTRACT_SUBREG GR64:$src2, subreg_32bit))>;
}
// Record that INSN performs a binary read-modify-write operation,
// with LOAD, OPERATOR and STORE being the read, modify and write
// respectively. MODE is the addressing mode and IMM is the type
// of the second operand.
class RMWI<SDPatternOperator load, SDPatternOperator operator,
SDPatternOperator store, AddressingMode mode,
PatFrag imm, Instruction insn>
: Pat<(store (operator (load mode:$addr), imm:$src), mode:$addr),
(insn mode:$addr, (UIMM8 imm:$src))>;
// Record that INSN performs binary operation OPERATION on a byte
// memory location. IMM is the type of the second operand.
multiclass RMWIByte<SDPatternOperator operator, AddressingMode mode,
Instruction insn> {
def : RMWI<anyextloadi8, operator, truncstorei8, mode, imm32, insn>;
def : RMWI<anyextloadi8, operator, truncstorei8, mode, imm64, insn>;
}
// Record that INSN performs insertion TYPE into a register of class CLS.
// The inserted operand is loaded using LOAD from an address of mode MODE.
multiclass InsertMem<string type, Instruction insn, RegisterOperand cls,
SDPatternOperator load, AddressingMode mode> {
def : Pat<(!cast<SDPatternOperator>("or_as_"##type)
cls:$src1, (load mode:$src2)),
(insn cls:$src1, mode:$src2)>;
def : Pat<(!cast<SDPatternOperator>("or_as_rev"##type)
(load mode:$src2), cls:$src1),
(insn cls:$src1, mode:$src2)>;
}
// Try to use MVC instruction INSN for a load of type LOAD followed by a store
// of the same size. VT is the type of the intermediate (legalized) value and
// LENGTH is the number of bytes loaded by LOAD.
multiclass MVCLoadStore<SDPatternOperator load, ValueType vt, Instruction insn,
bits<5> length> {
def : Pat<(mvc_store (vt (load bdaddr12only:$src)), bdaddr12only:$dest),
(insn bdaddr12only:$dest, bdaddr12only:$src, length)>;
}
// Use NC-like instruction INSN for block_op operation OPERATOR.
// The other operand is a load of type LOAD, which accesses LENGTH bytes.
// VT is the intermediate legalized type in which the binary operation
// is actually done.
multiclass BinaryLoadStore<SDPatternOperator operator, SDPatternOperator load,
ValueType vt, Instruction insn, bits<5> length> {
def : Pat<(operator (vt (load bdaddr12only:$src)), bdaddr12only:$dest),
(insn bdaddr12only:$dest, bdaddr12only:$src, length)>;
}
// A convenient way of generating all block peepholes for a particular
// LOAD/VT/LENGTH combination.
multiclass BlockLoadStore<SDPatternOperator load, ValueType vt,
Instruction mvc, Instruction nc, Instruction oc,
Instruction xc, bits<5> length> {
defm : MVCLoadStore<load, vt, mvc, length>;
defm : BinaryLoadStore<block_and1, load, vt, nc, length>;
defm : BinaryLoadStore<block_and2, load, vt, nc, length>;
defm : BinaryLoadStore<block_or1, load, vt, oc, length>;
defm : BinaryLoadStore<block_or2, load, vt, oc, length>;
defm : BinaryLoadStore<block_xor1, load, vt, xc, length>;
defm : BinaryLoadStore<block_xor2, load, vt, xc, length>;
}
// Record that INSN is a LOAD AND TEST that can be used to compare
// registers in CLS against zero. The instruction has separate R1 and R2
// operands, but they must be the same when the instruction is used like this.
class CompareZeroFP<Instruction insn, RegisterOperand cls>
: Pat<(z_fcmp cls:$reg, (fpimm0)), (insn cls:$reg, cls:$reg)>;