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Intel encodings for nearest/floor/ceil/trunc.

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These floating point rounding operations all use the roundss/roundsd
instructions that are available in SSE 4.1.
This commit is contained in:
Jakob Stoklund Olesen
2017-09-25 14:57:01 -07:00
parent ac343ba92a
commit 6bec5f8507
8 changed files with 216 additions and 14 deletions
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35
lib/cretonne/src/isa/intel/binemit.rs
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@@ -1,7 +1,7 @@
//! Emitting binary Intel machine code.
use binemit::{CodeSink, Reloc, bad_encoding};
use ir::{Function, Inst, Ebb, InstructionData};
use ir::{Function, Inst, Ebb, InstructionData, Opcode};
use isa::{RegUnit, StackRef, StackBase, StackBaseMask};
use regalloc::RegDiversions;
use super::registers::RU;
@@ -41,6 +41,9 @@ fn stk_base(base: StackBase) -> RegUnit {
// Mandatory prefix bytes for Mp* opcodes.
const PREFIX: [u8; 3] = [0x66, 0xf3, 0xf2];
// Second byte for three-byte opcodes for mm=0b10 and mm=0b11.
const OP3_BYTE2: [u8; 2] = [0x38, 0x3a];
// A REX prefix with no bits set: 0b0100WRXB.
const BASE_REX: u8 = 0b0100_0000;
@@ -111,6 +114,15 @@ fn put_mp1<CS: CodeSink + ?Sized>(bits: u16, rex: u8, sink: &mut CS) {
sink.put1(bits as u8);
}
// Emit single-byte opcode with mandatory prefix and REX.
fn put_rexmp1<CS: CodeSink + ?Sized>(bits: u16, rex: u8, sink: &mut CS) {
debug_assert_eq!(bits & 0x0c00, 0, "Invalid encoding bits for Mp1*");
let pp = (bits >> 8) & 3;
sink.put1(PREFIX[(pp - 1) as usize]);
rex_prefix(bits, rex, sink);
sink.put1(bits as u8);
}
// Emit two-byte opcode (0F XX) with mandatory prefix.
fn put_mp2<CS: CodeSink + ?Sized>(bits: u16, rex: u8, sink: &mut CS) {
debug_assert_eq!(bits & 0x8c00, 0x0400, "Invalid encoding bits for Mp2*");
@@ -131,12 +143,27 @@ fn put_rexmp2<CS: CodeSink + ?Sized>(bits: u16, rex: u8, sink: &mut CS) {
sink.put1(bits as u8);
}
// Emit single-byte opcode with mandatory prefix and REX.
fn put_rexmp1<CS: CodeSink + ?Sized>(bits: u16, rex: u8, sink: &mut CS) {
debug_assert_eq!(bits & 0x0c00, 0, "Invalid encoding bits for Mp1*");
// Emit three-byte opcode (0F 3[8A] XX) with mandatory prefix.
fn put_mp3<CS: CodeSink + ?Sized>(bits: u16, rex: u8, sink: &mut CS) {
debug_assert_eq!(bits & 0x8800, 0x0800, "Invalid encoding bits for Mp3*");
let pp = (bits >> 8) & 3;
sink.put1(PREFIX[(pp - 1) as usize]);
debug_assert_eq!(rex, BASE_REX, "Invalid registers for REX-less Mp3 encoding");
let mm = (bits >> 10) & 3;
sink.put1(0x0f);
sink.put1(OP3_BYTE2[(mm - 2) as usize]);
sink.put1(bits as u8);
}
// Emit three-byte opcode (0F 3[8A] XX) with mandatory prefix and REX
fn put_rexmp3<CS: CodeSink + ?Sized>(bits: u16, rex: u8, sink: &mut CS) {
debug_assert_eq!(bits & 0x0800, 0x0800, "Invalid encoding bits for Mp3*");
let pp = (bits >> 8) & 3;
sink.put1(PREFIX[(pp - 1) as usize]);
rex_prefix(bits, rex, sink);
let mm = (bits >> 10) & 3;
sink.put1(0x0f);
sink.put1(OP3_BYTE2[(mm - 2) as usize]);
sink.put1(bits as u8);
}