runtime: remove unnecessary NOFRAME flags on windows

This CL removes some NOFRAME flags on Windows assembly files
for several reasons:

- windows/386 does not use a frame pointer
- Leaf frameless functions already skip the frame pointer
- Some non-leaf functions do not contain enough dragons to justify
not using the frame pointer

Updates #58378

Change-Id: I31e71bf7f769e1957a4adba91778da5af66ce1e4
Reviewed-on: https://go-review.googlesource.com/c/go/+/466835
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Quim Muntal <quimmuntal@gmail.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

src/runtime/rt0_windows_amd64.s

@@ -6,7 +6,7 @@
 #include "go_tls.h"
 #include "textflag.h"
 
-TEXT _rt0_amd64_windows(SB),NOSPLIT,$-8
+TEXT _rt0_amd64_windows(SB),NOSPLIT|NOFRAME,$-8
 	JMP	_rt0_amd64(SB)
 
 // When building with -buildmode=(c-shared or c-archive), this
@@ -24,7 +24,7 @@ TEXT _rt0_amd64_windows_lib(SB),NOSPLIT|NOFRAME,$0x20
 	CALL	AX
 	RET
 
-TEXT _rt0_amd64_windows_lib_go(SB),NOSPLIT,$0
+TEXT _rt0_amd64_windows_lib_go(SB),NOSPLIT|NOFRAME,$0
 	MOVQ  $0, DI
 	MOVQ	$0, SI
 	MOVQ	$runtime·rt0_go(SB), AX

src/runtime/rt0_windows_arm64.s

@@ -23,7 +23,7 @@ TEXT _rt0_arm64_windows_lib_go(SB),NOSPLIT|NOFRAME,$0
 	MOVD	$runtime·rt0_go(SB), R2
 	B	(R2)
 
-TEXT main(SB),NOSPLIT,$0
+TEXT main(SB),NOSPLIT|NOFRAME,$0
 	MOVD	$runtime·rt0_go(SB), R2
 	B	(R2)
 

src/runtime/sys_windows_386.s

@@ -50,7 +50,7 @@ TEXT runtime·getlasterror(SB),NOSPLIT,$0
 	MOVL	AX, ret+0(FP)
 	RET
 
-TEXT runtime·sigFetchGSafe<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·sigFetchGSafe<ABIInternal>(SB),NOSPLIT,$0
 	get_tls(AX)
 	CMPL	AX, $0
 	JE	2(PC)
@@ -93,7 +93,7 @@ TEXT sigtramp<>(SB),NOSPLIT,$0-0
 // It switches stacks and jumps to the continuation address.
 // DX and CX are set above at the end of sigtrampgo
 // in the context that starts executing at sigresume.
-TEXT runtime·sigresume(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·sigresume(SB),NOSPLIT,$0
 	MOVL	DX, SP
 	JMP	CX
 
@@ -311,7 +311,7 @@ useQPC:
 
 // This is called from rt0_go, which runs on the system stack
 // using the initial stack allocated by the OS.
-TEXT runtime·wintls(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·wintls(SB),NOSPLIT,$0
 	// Allocate a TLS slot to hold g across calls to external code
 	MOVL	SP, BP
 	MOVL	runtime·_TlsAlloc(SB), AX

src/runtime/sys_windows_amd64.s

@@ -12,9 +12,12 @@
 #define TEB_TlsSlots 0x1480
 
 // void runtime·asmstdcall(void *c);
-TEXT runtime·asmstdcall(SB),NOSPLIT|NOFRAME,$0
-	// asmcgocall will put first argument into CX.
-	PUSHQ	CX			// save for later
+TEXT runtime·asmstdcall(SB),NOSPLIT,$16
+	MOVQ	SP, AX
+	ANDQ	$~15, SP	// alignment as per Windows requirement
+	MOVQ	AX, 8(SP)
+	MOVQ	CX, 0(SP)	// asmcgocall will put first argument into CX.
+
 	MOVQ	libcall_fn(CX), AX
 	MOVQ	libcall_args(CX), SI
 	MOVQ	libcall_n(CX), CX
@@ -61,7 +64,8 @@ loadregs:
 	ADDQ	$(const_maxArgs*8), SP
 
 	// Return result.
-	POPQ	CX
+	MOVQ	0(SP), CX
+	MOVQ	8(SP), SP
 	MOVQ	AX, libcall_r1(CX)
 	// Floating point return values are returned in XMM0. Setting r2 to this
 	// value in case this call returned a floating point value. For details,
@@ -233,7 +237,7 @@ TEXT runtime·settls(SB),NOSPLIT,$0
 // g may be nil.
 // The function leaves room for 4 syscall parameters
 // (as per windows amd64 calling convention).
-TEXT runtime·usleep2(SB),NOSPLIT|NOFRAME,$48-4
+TEXT runtime·usleep2(SB),NOSPLIT,$48-4
 	MOVLQSX	dt+0(FP), BX
 	MOVQ	SP, AX
 	ANDQ	$~15, SP	// alignment as per Windows requirement
@@ -249,7 +253,7 @@ TEXT runtime·usleep2(SB),NOSPLIT|NOFRAME,$48-4
 
 // Runs on OS stack. duration (in -100ns units) is in dt+0(FP).
 // g is valid.
-TEXT runtime·usleep2HighRes(SB),NOSPLIT|NOFRAME,$72-4
+TEXT runtime·usleep2HighRes(SB),NOSPLIT,$72-4
 	MOVLQSX	dt+0(FP), BX
 	get_tls(CX)
 
@@ -281,7 +285,7 @@ TEXT runtime·usleep2HighRes(SB),NOSPLIT|NOFRAME,$72-4
 	RET
 
 // Runs on OS stack.
-TEXT runtime·switchtothread(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·switchtothread(SB),NOSPLIT,$0
 	MOVQ	SP, AX
 	ANDQ	$~15, SP	// alignment as per Windows requirement
 	SUBQ	$(48), SP	// room for SP and 4 args as per Windows requirement
@@ -306,15 +310,15 @@ useQPC:
 
 // func osSetupTLS(mp *m)
 // Setup TLS. for use by needm on Windows.
-TEXT runtime·osSetupTLS(SB),NOSPLIT|NOFRAME,$0-8
+TEXT runtime·osSetupTLS(SB),NOSPLIT,$0-8
 	MOVQ	mp+0(FP), AX
 	LEAQ	m_tls(AX), DI
 	CALL	runtime·settls(SB)
 	RET
 
 // This is called from rt0_go, which runs on the system stack
 // using the initial stack allocated by the OS.
-TEXT runtime·wintls(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·wintls(SB),NOSPLIT,$0
 	// Allocate a TLS slot to hold g across calls to external code
 	MOVQ	SP, AX
 	ANDQ	$~15, SP	// alignment as per Windows requirement

src/runtime/sys_windows_arm.s

@@ -232,12 +232,12 @@ TEXT ·publicationBarrier(SB),NOSPLIT|NOFRAME,$0-0
 	B	runtime·armPublicationBarrier(SB)
 
 // never called (this is a GOARM=7 platform)
-TEXT runtime·read_tls_fallback(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·read_tls_fallback(SB),NOSPLIT,$0
 	MOVW	$0xabcd, R0
 	MOVW	R0, (R0)
 	RET
 
-TEXT runtime·nanotime1(SB),NOSPLIT|NOFRAME,$0-8
+TEXT runtime·nanotime1(SB),NOSPLIT,$0-8
 	MOVW	$0, R0
 	MOVB	runtime·useQPCTime(SB), R0
 	CMP	$0, R0
@@ -262,7 +262,7 @@ loop:
 	MOVW	R4, ret_hi+4(FP)
 	RET
 useQPC:
-	B	runtime·nanotimeQPC(SB)		// tail call
+	RET	runtime·nanotimeQPC(SB)		// tail call
 
 // save_g saves the g register (R10) into thread local memory
 // so that we can call externally compiled
@@ -273,7 +273,7 @@ useQPC:
 // Save the value in the _TEB->TlsSlots array.
 // Effectively implements TlsSetValue().
 // tls_g stores the TLS slot allocated TlsAlloc().
-TEXT runtime·save_g(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·save_g(SB),NOSPLIT,$0
 	MRC	15, 0, R0, C13, C0, 2
 	ADD	$0xe10, R0
 	MOVW 	$runtime·tls_g(SB), R11
@@ -287,7 +287,7 @@ TEXT runtime·save_g(SB),NOSPLIT|NOFRAME,$0
 // ARM code that overwrote those registers.
 // Get the value from the _TEB->TlsSlots array.
 // Effectively implements TlsGetValue().
-TEXT runtime·load_g(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·load_g(SB),NOSPLIT,$0
 	MRC	15, 0, R0, C13, C0, 2
 	ADD	$0xe10, R0
 	MOVW 	$runtime·tls_g(SB), g

src/runtime/sys_windows_arm64.s

@@ -19,8 +19,7 @@
 // load_g and save_g (in tls_arm64.s) clobber R27 (REGTMP) and R0.
 
 // void runtime·asmstdcall(void *c);
-TEXT runtime·asmstdcall(SB),NOSPLIT|NOFRAME,$0
-	STP.W	(R29, R30), -32(RSP)	// allocate C ABI stack frame
+TEXT runtime·asmstdcall(SB),NOSPLIT,$16
 	STP	(R19, R20), 16(RSP) // save old R19, R20
 	MOVD	R0, R19	// save libcall pointer
 	MOVD	RSP, R20	// save stack pointer
@@ -96,10 +95,9 @@ _0args:
 
 	// Restore callee-saved registers.
 	LDP	16(RSP), (R19, R20)
-	LDP.P	32(RSP), (R29, R30)
 	RET
 
-TEXT runtime·getlasterror(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·getlasterror(SB),NOSPLIT,$0
 	MOVD	TEB_error(R18_PLATFORM), R0
 	MOVD	R0, ret+0(FP)
 	RET
@@ -245,7 +243,7 @@ TEXT runtime·usleep2(SB),NOSPLIT,$32-4
 // duration (in -100ns units) is in dt+0(FP).
 // g is valid.
 // TODO: needs to be implemented properly.
-TEXT runtime·usleep2HighRes(SB),NOSPLIT,$0-4
+TEXT runtime·usleep2HighRes(SB),NOSPLIT|NOFRAME,$0-4
 	B	runtime·abort(SB)
 
 // Runs on OS stack.
@@ -256,7 +254,7 @@ TEXT runtime·switchtothread(SB),NOSPLIT,$16-0
 	ADD	$16, RSP
 	RET
 
-TEXT runtime·nanotime1(SB),NOSPLIT|NOFRAME,$0-8
+TEXT runtime·nanotime1(SB),NOSPLIT,$0-8
 	MOVB	runtime·useQPCTime(SB), R0
 	CMP	$0, R0
 	BNE	useQPC
@@ -267,7 +265,7 @@ TEXT runtime·nanotime1(SB),NOSPLIT|NOFRAME,$0-8
 	MOVD	R0, ret+0(FP)
 	RET
 useQPC:
-	B	runtime·nanotimeQPC(SB)		// tail call
+	RET	runtime·nanotimeQPC(SB)		// tail call
 
 // This is called from rt0_go, which runs on the system stack
 // using the initial stack allocated by the OS.

src/runtime/time_windows_arm.s

@@ -8,7 +8,7 @@
 #include "textflag.h"
 #include "time_windows.h"
 
-TEXT time·now(SB),NOSPLIT|NOFRAME,$0-20
+TEXT time·now(SB),NOSPLIT,$0-20
 	MOVW    $0, R0
 	MOVB    runtime·useQPCTime(SB), R0
 	CMP	$0, R0
@@ -86,5 +86,5 @@ wall:
 	MOVW	R1,nsec+8(FP)
 	RET
 useQPC:
-	B	runtime·nowQPC(SB)		// tail call
+	RET	runtime·nowQPC(SB)		// tail call
 

src/runtime/time_windows_arm64.s

@@ -8,7 +8,7 @@
 #include "textflag.h"
 #include "time_windows.h"
 
-TEXT time·now(SB),NOSPLIT|NOFRAME,$0-24
+TEXT time·now(SB),NOSPLIT,$0-24
 	MOVB    runtime·useQPCTime(SB), R0
 	CMP	$0, R0
 	BNE	useQPC
@@ -43,5 +43,5 @@ TEXT time·now(SB),NOSPLIT|NOFRAME,$0-24
 	MOVW	R0, nsec+8(FP)
 	RET
 useQPC:
-	B	runtime·nowQPC(SB)		// tail call
+	RET	runtime·nowQPC(SB)		// tail call