feat(amd64): LOCK and REP prefixes, literal data pseudo-ops and ADJSP

Assisted-by: GLM 5.3 Flash
2026-09-20 14:25:47 +02:00
parent 9dc3987e02
commit dce5d31462
8 changed files with 581 additions and 1 deletions
@@ -0,0 +1,62 @@
+// Literal data emission: BYTE, WORD, LONG and QUAD write the immediate
+// into the text stream as 1, 2, 4 or 8 little-endian bytes with no opcode
+// lookup, truncated to the width rather than range-checked; END is
+// accepted and ignored, contributing no bytes and ending nothing.  The
+// shapes mirror the runtime's hand-laid markers
+// (crypto/internal/boring/sig/sig_amd64.s) and its syscall stubs
+// (runtime/sys_linux_amd64.s).
+
+#include "textflag.h"
+
+// func marker()
+// A boring/crypto-style marker: a hand-laid forward branch whose skip
+// distance is patched at runtime.  One BYTE per statement, as the
+// runtime's own file spells it: the semicolon-separated one-liner the
+// sys_linux_amd64.s stub uses does not survive gasm fmt, which drops the
+// statement separators.
+TEXT ·marker(SB), NOSPLIT, $0-0
+	BYTE $0xEB
+	BYTE $0x1D
+	BYTE $0xF4
+	BYTE $0x48
+	BYTE $0xF4
+	BYTE $0x4B
+	BYTE $0xC3
+	RET
+
+// func stub()
+// The sys_linux_amd64.s stub bytes: the sign-extended
+// "48 c7 c0 0f 00 00 00" form of MOVQ $rt_sigreturn, AX.
+TEXT ·stub(SB), NOSPLIT, $0-0
+	BYTE $0x48
+	BYTE $0xc7
+	BYTE $0xc0
+	BYTE $0x0f
+	BYTE $0x00
+	BYTE $0x00
+	BYTE $0x00
+	RET
+
+// func words()
+// The wider literals, and an END that ends nothing: the WORD after it
+// still lands in this function.
+TEXT ·words(SB), NOSPLIT, $0-0
+	WORD $0x1234
+	WORD $-1
+	LONG $0x11223344
+	LONG $-1
+	QUAD $0x1122334455667788
+	QUAD $-2
+	END
+	WORD $0xBEEF
+	RET
+
+// func trunc()
+// Truncation, not a range check: each literal keeps its low bytes, exactly
+// as go tool asm emits them.
+TEXT ·trunc(SB), NOSPLIT, $0-0
+	BYTE $0x1FF
+	WORD $0x12345
+	LONG $0x123456789
+	QUAD $-2
+	RET