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Merge pull request #2414 from jgouly/extend-refactor

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arm64: Refactor Inst::Extend handling
This commit is contained in:
Chris Fallin
2020-11-25 17:22:07 -08:00
committed by GitHub
parent 31bac3eafb 70cbc4ca7c
commit d413b907b4
8 changed files with 256 additions and 187 deletions
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136
cranelift/codegen/src/isa/aarch64/inst/emit.rs
View File

@@ -258,10 +258,6 @@ fn enc_ldst_vec(q: u32, size: u32, rn: Reg, rt: Writable<Reg>) -> u32 {
| machreg_to_vec(rt.to_reg())
}
fn enc_extend(top22: u32, rd: Writable<Reg>, rn: Reg) -> u32 {
(top22 << 10) | (machreg_to_gpr(rn) << 5) | machreg_to_gpr(rd.to_reg())
}
fn enc_vec_rrr(top11: u32, rm: Reg, bit15_10: u32, rn: Reg, rd: Writable<Reg>) -> u32 {
(top11 << 21)
| (machreg_to_vec(rm) << 16)
@@ -313,6 +309,12 @@ fn enc_cset(rd: Writable<Reg>, cond: Cond) -> u32 {
| (cond.invert().bits() << 12)
}
fn enc_csetm(rd: Writable<Reg>, cond: Cond) -> u32 {
0b110_11010100_11111_0000_00_11111_00000
| machreg_to_gpr(rd.to_reg())
| (cond.invert().bits() << 12)
}
fn enc_ccmp_imm(size: OperandSize, rn: Reg, imm: UImm5, nzcv: NZCV, cond: Cond) -> u32 {
0b0_1_1_11010010_00000_0000_10_00000_0_0000
| size.sf_bit() << 31
@@ -322,6 +324,29 @@ fn enc_ccmp_imm(size: OperandSize, rn: Reg, imm: UImm5, nzcv: NZCV, cond: Cond)
| nzcv.bits()
}
fn enc_bfm(opc: u8, size: OperandSize, rd: Writable<Reg>, rn: Reg, immr: u8, imms: u8) -> u32 {
match size {
OperandSize::Size64 => {
debug_assert!(immr <= 63);
debug_assert!(imms <= 63);
}
OperandSize::Size32 => {
debug_assert!(immr <= 31);
debug_assert!(imms <= 31);
}
}
debug_assert_eq!(opc & 0b11, opc);
let n_bit = size.sf_bit();
0b0_00_100110_0_000000_000000_00000_00000
| size.sf_bit() << 31
| u32::from(opc) << 29
| n_bit << 22
| u32::from(immr) << 16
| u32::from(imms) << 10
| machreg_to_gpr(rn) << 5
| machreg_to_gpr(rd.to_reg())
}
fn enc_vecmov(is_16b: bool, rd: Writable<Reg>, rn: Reg) -> u32 {
0b00001110_101_00000_00011_1_00000_00000
| ((is_16b as u32) << 30)
@@ -1045,6 +1070,9 @@ impl MachInstEmit for Inst {
&Inst::CSet { rd, cond } => {
sink.put4(enc_cset(rd, cond));
}
&Inst::CSetm { rd, cond } => {
sink.put4(enc_csetm(rd, cond));
}
&Inst::CCmpImm {
size,
rn,
@@ -1985,75 +2013,47 @@ impl MachInstEmit for Inst {
&Inst::Extend {
rd,
rn,
signed,
from_bits,
signed: false,
from_bits: 1,
to_bits,
} if from_bits >= 8 => {
let top22 = match (signed, from_bits, to_bits) {
(false, 8, 32) => 0b010_100110_0_000000_000111, // UXTB (32)
(false, 16, 32) => 0b010_100110_0_000000_001111, // UXTH (32)
(true, 8, 32) => 0b000_100110_0_000000_000111, // SXTB (32)
(true, 16, 32) => 0b000_100110_0_000000_001111, // SXTH (32)
// The 64-bit unsigned variants are the same as the 32-bit ones,
// because writes to Wn zero out the top 32 bits of Xn
(false, 8, 64) => 0b010_100110_0_000000_000111, // UXTB (64)
(false, 16, 64) => 0b010_100110_0_000000_001111, // UXTH (64)
(true, 8, 64) => 0b100_100110_1_000000_000111, // SXTB (64)
(true, 16, 64) => 0b100_100110_1_000000_001111, // SXTH (64)
// 32-to-64: the unsigned case is a 'mov' (special-cased below).
(false, 32, 64) => 0, // MOV
(true, 32, 64) => 0b100_100110_1_000000_011111, // SXTW (64)
_ => panic!(
"Unsupported extend combination: signed = {}, from_bits = {}, to_bits = {}",
signed, from_bits, to_bits
),
};
if top22 != 0 {
sink.put4(enc_extend(top22, rd, rn));
} else {
let mov = Inst::Mov32 { rd, rm: rn };
mov.emit(sink, emit_info, state);
}
}
&Inst::Extend {
rd,
rn,
signed,
from_bits,
to_bits,
} if from_bits == 1 && signed => {
assert!(to_bits <= 64);
// Reduce sign-extend-from-1-bit to:
// - and rd, rn, #1
// - sub rd, zr, rd
// We don't have ImmLogic yet, so we just hardcode this. FIXME.
sink.put4(0x92400000 | (machreg_to_gpr(rn) << 5) | machreg_to_gpr(rd.to_reg()));
let sub_inst = Inst::AluRRR {
alu_op: ALUOp::Sub64,
rd,
rn: zero_reg(),
rm: rd.to_reg(),
};
sub_inst.emit(sink, emit_info, state);
}
&Inst::Extend {
rd,
rn,
signed,
from_bits,
to_bits,
} if from_bits == 1 && !signed => {
} => {
assert!(to_bits <= 64);
// Reduce zero-extend-from-1-bit to:
// - and rd, rn, #1
// We don't have ImmLogic yet, so we just hardcode this. FIXME.
sink.put4(0x92400000 | (machreg_to_gpr(rn) << 5) | machreg_to_gpr(rd.to_reg()));
// Note: This is special cased as UBFX may take more cycles
// than AND on smaller cores.
let imml = ImmLogic::maybe_from_u64(1, I32).unwrap();
Inst::AluRRImmLogic {
alu_op: ALUOp::And32,
rd,
rn,
imml,
}
.emit(sink, emit_info, state);
}
&Inst::Extend { .. } => {
panic!("Unsupported extend variant");
&Inst::Extend {
rd,
rn,
signed: false,
from_bits: 32,
to_bits: 64,
} => {
let mov = Inst::Mov32 { rd, rm: rn };
mov.emit(sink, emit_info, state);
}
&Inst::Extend {
rd,
rn,
signed,
from_bits,
to_bits,
} => {
let (opc, size) = if signed {
(0b00, OperandSize::from_bits(to_bits))
} else {
(0b10, OperandSize::Size32)
};
sink.put4(enc_bfm(opc, size, rd, rn, 0, from_bits - 1));
}
&Inst::Jump { ref dest } => {
let off = sink.cur_offset();

64
cranelift/codegen/src/isa/aarch64/inst/emit_tests.rs
View File

@@ -1846,6 +1846,22 @@ fn test_aarch64_binemit() {
"EFB79F9A",
"cset x15, ge",
));
insns.push((
Inst::CSetm {
rd: writable_xreg(0),
cond: Cond::Eq,
},
"E0139FDA",
"csetm x0, eq",
));
insns.push((
Inst::CSetm {
rd: writable_xreg(16),
cond: Cond::Vs,
},
"F0739FDA",
"csetm x16, vs",
));
insns.push((
Inst::CCmpImm {
size: OperandSize::Size64,
@@ -3952,6 +3968,50 @@ fn test_aarch64_binemit() {
"vcsel v5.16b, v10.16b, v19.16b, gt (if-then-else diamond)",
));
insns.push((
Inst::Extend {
rd: writable_xreg(3),
rn: xreg(5),
signed: false,
from_bits: 1,
to_bits: 32,
},
"A3000012",
"and w3, w5, #1",
));
insns.push((
Inst::Extend {
rd: writable_xreg(3),
rn: xreg(5),
signed: false,
from_bits: 1,
to_bits: 64,
},
"A3000012",
"and w3, w5, #1",
));
insns.push((
Inst::Extend {
rd: writable_xreg(10),
rn: xreg(21),
signed: true,
from_bits: 1,
to_bits: 32,
},
"AA020013",
"sbfx w10, w21, #0, #1",
));
insns.push((
Inst::Extend {
rd: writable_xreg(1),
rn: xreg(2),
signed: true,
from_bits: 1,
to_bits: 64,
},
"41004093",
"sbfx x1, x2, #0, #1",
));
insns.push((
Inst::Extend {
rd: writable_xreg(1),
@@ -4005,7 +4065,7 @@ fn test_aarch64_binemit() {
to_bits: 64,
},
"411C0053",
"uxtb x1, w2",
"uxtb w1, w2",
));
insns.push((
Inst::Extend {
@@ -4027,7 +4087,7 @@ fn test_aarch64_binemit() {
to_bits: 64,
},
"413C0053",
"uxth x1, w2",
"uxth w1, w2",
));
insns.push((
Inst::Extend {

116
cranelift/codegen/src/isa/aarch64/inst/mod.rs
View File

@@ -661,6 +661,12 @@ pub enum Inst {
cond: Cond,
},
/// A conditional-set-mask operation.
CSetm {
rd: Writable<Reg>,
cond: Cond,
},
/// A conditional comparison with an immediate.
CCmpImm {
size: OperandSize,
@@ -1674,7 +1680,7 @@ fn aarch64_get_regs(inst: &Inst, collector: &mut RegUsageCollector) {
collector.add_use(rn);
collector.add_use(rm);
}
&Inst::CSet { rd, .. } => {
&Inst::CSet { rd, .. } | &Inst::CSetm { rd, .. } => {
collector.add_def(rd);
}
&Inst::CCmpImm { rn, .. } => {
@@ -2242,7 +2248,7 @@ fn aarch64_map_regs<RUM: RegUsageMapper>(inst: &mut Inst, mapper: &RUM) {
map_use(mapper, rn);
map_use(mapper, rm);
}
&mut Inst::CSet { ref mut rd, .. } => {
&mut Inst::CSet { ref mut rd, .. } | &mut Inst::CSetm { ref mut rd, .. } => {
map_def(mapper, rd);
}
&mut Inst::CCmpImm { ref mut rn, .. } => {
@@ -3157,6 +3163,11 @@ impl Inst {
let cond = cond.show_rru(mb_rru);
format!("cset {}, {}", rd, cond)
}
&Inst::CSetm { rd, cond } => {
let rd = rd.to_reg().show_rru(mb_rru);
let cond = cond.show_rru(mb_rru);
format!("csetm {}, {}", rd, cond)
}
&Inst::CCmpImm {
size,
rn,
@@ -3737,63 +3748,60 @@ impl Inst {
&Inst::Extend {
rd,
rn,
signed,
from_bits,
to_bits,
} if from_bits >= 8 => {
// Is the destination a 32-bit register? Corresponds to whether
// extend-to width is <= 32 bits, *unless* we have an unsigned
// 32-to-64-bit extension, which is implemented with a "mov" to a
// 32-bit (W-reg) dest, because this zeroes the top 32 bits.
let dest_size = if !signed && from_bits == 32 && to_bits == 64 {
OperandSize::Size32
} else {
OperandSize::from_bits(to_bits)
};
let rd = show_ireg_sized(rd.to_reg(), mb_rru, dest_size);
let rn = show_ireg_sized(rn, mb_rru, OperandSize::from_bits(from_bits));
let op = match (signed, from_bits, to_bits) {
(false, 8, 32) => "uxtb",
(true, 8, 32) => "sxtb",
(false, 16, 32) => "uxth",
(true, 16, 32) => "sxth",
(false, 8, 64) => "uxtb",
(true, 8, 64) => "sxtb",
(false, 16, 64) => "uxth",
(true, 16, 64) => "sxth",
(false, 32, 64) => "mov", // special case (see above).
(true, 32, 64) => "sxtw",
_ => panic!("Unsupported Extend case: {:?}", self),
};
format!("{} {}, {}", op, rd, rn)
}
&Inst::Extend {
rd,
rn,
signed,
from_bits,
to_bits,
} if from_bits == 1 && signed => {
let dest_size = OperandSize::from_bits(to_bits);
let zr = if dest_size.is32() { "wzr" } else { "xzr" };
let rd32 = show_ireg_sized(rd.to_reg(), mb_rru, OperandSize::Size32);
let rd = show_ireg_sized(rd.to_reg(), mb_rru, dest_size);
let rn = show_ireg_sized(rn, mb_rru, OperandSize::Size32);
format!("and {}, {}, #1 ; sub {}, {}, {}", rd32, rn, rd, zr, rd)
}
&Inst::Extend {
rd,
rn,
signed,
from_bits,
signed: false,
from_bits: 1,
..
} if from_bits == 1 && !signed => {
} => {
let rd = show_ireg_sized(rd.to_reg(), mb_rru, OperandSize::Size32);
let rn = show_ireg_sized(rn, mb_rru, OperandSize::Size32);
format!("and {}, {}, #1", rd, rn)
}
&Inst::Extend { .. } => {
panic!("Unsupported Extend case");
&Inst::Extend {
rd,
rn,
signed: false,
from_bits: 32,
to_bits: 64,
} => {
// The case of a zero extension from 32 to 64 bits, is implemented
// with a "mov" to a 32-bit (W-reg) dest, because this zeroes
// the top 32 bits.
let rd = show_ireg_sized(rd.to_reg(), mb_rru, OperandSize::Size32);
let rn = show_ireg_sized(rn, mb_rru, OperandSize::Size32);
format!("mov {}, {}", rd, rn)
}
&Inst::Extend {
rd,
rn,
signed,
from_bits,
to_bits,
} => {
assert!(from_bits <= to_bits);
let op = match (signed, from_bits) {
(false, 8) => "uxtb",
(true, 8) => "sxtb",
(false, 16) => "uxth",
(true, 16) => "sxth",
(true, 32) => "sxtw",
(true, _) => "sbfx",
(false, _) => "ubfx",
};
if op == "sbfx" || op == "ubfx" {
let dest_size = OperandSize::from_bits(to_bits);
let rd = show_ireg_sized(rd.to_reg(), mb_rru, dest_size);
let rn = show_ireg_sized(rn, mb_rru, dest_size);
format!("{} {}, {}, #0, #{}", op, rd, rn, from_bits)
} else {
let dest_size = if signed {
OperandSize::from_bits(to_bits)
} else {
OperandSize::Size32
};
let rd = show_ireg_sized(rd.to_reg(), mb_rru, dest_size);
let rn = show_ireg_sized(rn, mb_rru, OperandSize::from_bits(from_bits));
format!("{} {}, {}", op, rd, rn)
}
}
&Inst::Call { .. } => format!("bl 0"),
&Inst::CallInd { ref info, .. } => {