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Infer REX prefix for SIMD operations; fixes #1127

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- Convert recipes to have necessary size calculator
- Add a missing binemit function, `put_dynrexmp3`
- Modify the meta-encodings of x86 SIMD instructions to use `infer_rex()`, mostly through the `enc_both_inferred()` helper
- Fix up tests that previously always emitted a REX prefix
This commit is contained in:
Andrew Brown
2020-03-16 18:22:21 -07:00
parent 381d43e40e
commit 0d63bd12d8
7 changed files with 257 additions and 185 deletions
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21
cranelift/codegen/src/isa/x86/binemit.rs
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@@ -197,7 +197,7 @@ fn put_dynrexmp2<CS: CodeSink + ?Sized>(bits: u16, rex: u8, sink: &mut CS) {
sink.put1(bits as u8);
}
// Emit three-byte opcode (0F 3[8A] XX) with mandatory prefix.
/// 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*");
debug_assert_eq!(rex, BASE_REX, "Invalid registers for REX-less Mp3 encoding");
@@ -208,7 +208,7 @@ fn put_mp3<CS: CodeSink + ?Sized>(bits: u16, rex: u8, sink: &mut CS) {
sink.put1(bits as u8);
}
// Emit three-byte opcode (0F 3[8A] XX) with mandatory prefix and REX
/// 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 RexMp3*");
let enc = EncodingBits::from(bits);
@@ -219,6 +219,23 @@ fn put_rexmp3<CS: CodeSink + ?Sized>(bits: u16, rex: u8, sink: &mut CS) {
sink.put1(bits as u8);
}
/// Emit three-byte opcode (0F 3[8A] XX) with mandatory prefix and an inferred REX prefix.
fn put_dynrexmp3<CS: CodeSink + ?Sized>(bits: u16, rex: u8, sink: &mut CS) {
debug_assert_eq!(
bits & 0x0800,
0x0800,
"Invalid encoding bits for DynRexMp3*"
);
let enc = EncodingBits::from(bits);
sink.put1(PREFIX[(enc.pp() - 1) as usize]);
if needs_rex(bits, rex) {
rex_prefix(bits, rex, sink);
}
sink.put1(0x0f);
sink.put1(OP3_BYTE2[(enc.mm() - 2) as usize]);
sink.put1(bits as u8);
}
/// Defines the EVEX context for the `L'`, `L`, and `b` bits (bits 6:4 of EVEX P2 byte). Table 2-36 in
/// section 2.6.10 (Intel Software Development Manual, volume 2A) describes how these bits can be
/// used together for certain classes of instructions; i.e., special care should be taken to ensure