From 6392b43a1583f5ccf5a3f7c38f096e8dd5403b0d Mon Sep 17 00:00:00 2001
From: Shenghou Ma <minux.ma@gmail.com>
Date: Mon, 6 Feb 2012 12:49:28 -0500
Subject: [PATCH] 8a, 8l: implement support for RDTSC instruction.         Also
 modify runtime/asm_386.s to use it.

R=rsc
CC=golang-dev
https://golang.org/cl/5634043
---
 src/cmd/8a/lex.c          | 1 +
 src/cmd/8l/8.out.h        | 4 +++-
 src/cmd/8l/optab.c        | 2 ++
 src/pkg/runtime/asm_386.s | 2 +-
 4 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/cmd/8a/lex.c b/src/cmd/8a/lex.c
index 403669404e6..254deab6a4d 100644
--- a/src/cmd/8a/lex.c
+++ b/src/cmd/8a/lex.c
@@ -445,6 +445,7 @@ struct
 	"RCRB",		LTYPE3,	ARCRB,
 	"RCRL",		LTYPE3,	ARCRL,
 	"RCRW",		LTYPE3,	ARCRW,
+	"RDTSC",	LTYPE0,	ARDTSC,
 	"REP",		LTYPE0,	AREP,
 	"REPN",		LTYPE0,	AREPN,
 	"RET",		LTYPE0,	ARET,
diff --git a/src/cmd/8l/8.out.h b/src/cmd/8l/8.out.h
index 5e4b73ad096..e8f530664b3 100644
--- a/src/cmd/8l/8.out.h
+++ b/src/cmd/8l/8.out.h
@@ -395,7 +395,9 @@ enum	as
 	ACMPXCHGL,
 	ACMPXCHGW,
 	ACMPXCHG8B,
-	
+
+	ARDTSC,
+
 	AXADDB,
 	AXADDL,
 	AXADDW,
diff --git a/src/cmd/8l/optab.c b/src/cmd/8l/optab.c
index 69602d704a2..c7700aa792f 100644
--- a/src/cmd/8l/optab.c
+++ b/src/cmd/8l/optab.c
@@ -707,6 +707,8 @@ Optab optab[] =
 	{ ACMPXCHGW,	yrl_ml,	Pm, 0xb1 },
 	{ ACMPXCHG8B,	yscond,	Pm, 0xc7,(01) },
 
+	{ ARDTSC,	ynone,	Pm, 0x31 },
+
 	{ AXADDB,	yrb_mb,	Pb, 0x0f,0xc0 },
 	{ AXADDL,	yrl_ml,	Pm, 0xc1 },
 	{ AXADDW,	yrl_ml,	Pe, 0x0f,0xc1 },
diff --git a/src/pkg/runtime/asm_386.s b/src/pkg/runtime/asm_386.s
index c242af82964..a4f94601dc3 100644
--- a/src/pkg/runtime/asm_386.s
+++ b/src/pkg/runtime/asm_386.s
@@ -527,7 +527,7 @@ TEXT runtime·getcallersp(SB), 7, $0
 // int64 runtime·cputicks(void), so really
 // void runtime·cputicks(int64 *ticks)
 TEXT runtime·cputicks(SB),7,$0
-	BYTE	$0x0F; BYTE $0x31;     // RDTSC; not supported by 8a
+	RDTSC
 	MOVL	ret+0(FP), DI
 	MOVL	AX, 0(DI)
 	MOVL	DX, 4(DI)