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Add support for Saturating Rounding Q-format Multiplication for x64

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This commit is contained in:
Johnnie Birch
2021-07-14 09:23:58 -07:00
parent ffec1f9b41
commit 5deda27977
4 changed files with 42 additions and 4 deletions
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40
cranelift/codegen/src/isa/x64/lower.rs
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@@ -6406,6 +6406,42 @@ fn lower_insn_to_regs<C: LowerCtx<I = Inst>>(
}
},
Opcode::SqmulRoundSat => {
// Lane-wise saturating rounding multiplication in Q15 format
// Optimal lowering taken from instruction proposal https://github.com/WebAssembly/simd/pull/365
// y = i16x8.q15mulr_sat_s(a, b) is lowered to:
//MOVDQA xmm_y, xmm_a
//MOVDQA xmm_tmp, wasm_i16x8_splat(0x8000)
//PMULHRSW xmm_y, xmm_b
//PCMPEQW xmm_tmp, xmm_y
//PXOR xmm_y, xmm_tmp
let input_ty = ctx.input_ty(insn, 0);
let src1 = put_input_in_reg(ctx, inputs[0]);
let src2 = put_input_in_reg(ctx, inputs[1]);
let dst = get_output_reg(ctx, outputs[0]).only_reg().unwrap();
ctx.emit(Inst::gen_move(dst, src1, input_ty));
static SAT_MASK: [u8; 16] = [
0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80,
0x00, 0x80,
];
let mask_const = ctx.use_constant(VCodeConstantData::WellKnown(&SAT_MASK));
let mask = ctx.alloc_tmp(types::I16X8).only_reg().unwrap();
ctx.emit(Inst::xmm_load_const(mask_const, mask, types::I16X8));
ctx.emit(Inst::xmm_rm_r(SseOpcode::Pmulhrsw, RegMem::reg(src2), dst));
ctx.emit(Inst::xmm_rm_r(
SseOpcode::Pcmpeqw,
RegMem::reg(dst.to_reg()),
mask,
));
ctx.emit(Inst::xmm_rm_r(
SseOpcode::Pxor,
RegMem::reg(mask.to_reg()),
dst,
));
}
// Unimplemented opcodes below. These are not currently used by Wasm
// lowering or other known embeddings, but should be either supported or
// removed eventually.
@@ -6436,8 +6472,8 @@ fn lower_insn_to_regs<C: LowerCtx<I = Inst>>(
unimplemented!("Vector split/concat ops not implemented.");
}
Opcode::SqmulRoundSat | Opcode::Uunarrow => {
unimplemented!("unimplemented lowering for opcode {:?}", op)
Opcode::Uunarrow => {
unimplemented!("unimplemented lowering for opcode {:?}", op);
}
// Opcodes that should be removed by legalization. These should