internal/bytealg: port more performance-critical functions to ABIInternal

CL 308931 ported several runtime assembly functions to ABIInternal so
that compiler-generated ABIInternal calls don't go through ABI
wrappers, but it missed the runtime assembly functions that are
actually defined in internal/bytealg.

This eliminates the cost of wrappers for the BleveQuery and
GopherLuaKNucleotide benchmarks, but there's still more to do for
Tile38.

                                      0-base                1-wrappers
                                     sec/op        sec/op            vs base
BleveQuery                          6.507 ± 0%    6.477 ± 0%  -0.46% (p=0.004 n=20)
GopherLuaKNucleotide                30.39 ± 1%    30.34 ± 0%       ~ (p=0.301 n=20)
Tile38IntersectsCircle100kmRequest 1.038m ± 1%   1.080m ± 2%  +4.03% (p=0.000 n=20)

For #40724.

Change-Id: I0b722443f684fcb997b1d70802c5ed4b8d8f9829
Reviewed-on: https://go-review.googlesource.com/c/go/+/310184
Trust: Austin Clements <austin@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

src/cmd/dist/build.go

@@ -1764,8 +1764,9 @@ func cmdlist() {
 // IsRuntimePackagePath examines 'pkgpath' and returns TRUE if it
 // belongs to the collection of "runtime-related" packages, including
 // "runtime" itself, "reflect", "syscall", and the
-// "runtime/internal/*" packages. See also the function of the same
+// "runtime/internal/*" packages.
-// name in cmd/internal/objabi/path.go.
+//
+// Keep in sync with cmd/internal/objabi/path.go:IsRuntimePackagePath.
 func IsRuntimePackagePath(pkgpath string) bool {
 	rval := false
 	switch pkgpath {
@@ -1777,6 +1778,8 @@ func IsRuntimePackagePath(pkgpath string) bool {
 		rval = true
 	case "crypto/x509/internal/macos": // libc function wrappers need to be ABIInternal
 		rval = true
+	case "internal/bytealg":
+		rval = true
 	default:
 		rval = strings.HasPrefix(pkgpath, "runtime/internal")
 	}

src/cmd/internal/objabi/path.go

@@ -47,6 +47,8 @@ func PathToPrefix(s string) string {
 // some cases need to be aware of when they are building such a
 // package, for example to enable features such as ABI selectors in
 // assembly sources.
+//
+// Keep in sync with cmd/dist/build.go:IsRuntimePackagePath.
 func IsRuntimePackagePath(pkgpath string) bool {
 	rval := false
 	switch pkgpath {
@@ -58,6 +60,8 @@ func IsRuntimePackagePath(pkgpath string) bool {
 		rval = true
 	case "crypto/x509/internal/macos": // libc function wrappers need to be ABIInternal
 		rval = true
+	case "internal/bytealg":
+		rval = true
 	default:
 		rval = strings.HasPrefix(pkgpath, "runtime/internal")
 	}

src/internal/bytealg/compare_amd64.s

@@ -5,20 +5,41 @@
 #include "go_asm.h"
 #include "textflag.h"
 
-TEXT ·Compare(SB),NOSPLIT,$0-56
+TEXT ·Compare<ABIInternal>(SB),NOSPLIT,$0-56
+#ifdef GOEXPERIMENT_regabiargs
+	// AX = a_base (want in SI)
+	// BX = a_len  (want in BX)
+	// CX = a_cap  (unused)
+	// DI = b_base (want in DI)
+	// SI = b_len  (want in DX)
+	// R8 = b_cap  (unused)
+	MOVQ	SI, DX
+	MOVQ	AX, SI
+#else
 	MOVQ	a_base+0(FP), SI
 	MOVQ	a_len+8(FP), BX
 	MOVQ	b_base+24(FP), DI
 	MOVQ	b_len+32(FP), DX
 	LEAQ	ret+48(FP), R9
+#endif
 	JMP	cmpbody<>(SB)
 
-TEXT runtime·cmpstring(SB),NOSPLIT,$0-40
+TEXT runtime·cmpstring<ABIInternal>(SB),NOSPLIT,$0-40
+#ifdef GOEXPERIMENT_regabiargs
+	// AX = a_base (want in SI)
+	// BX = a_len  (want in BX)
+	// CX = b_base (want in DI)
+	// DI = b_len  (want in DX)
+	MOVQ	AX, SI
+	MOVQ	DI, DX
+	MOVQ	CX, DI
+#else
 	MOVQ	a_base+0(FP), SI
 	MOVQ	a_len+8(FP), BX
 	MOVQ	b_base+16(FP), DI
 	MOVQ	b_len+24(FP), DX
 	LEAQ	ret+32(FP), R9
+#endif
 	JMP	cmpbody<>(SB)
 
 // input:
@@ -26,7 +47,12 @@ TEXT runtime·cmpstring(SB),NOSPLIT,$0-40
 //   DI = b
 //   BX = alen
 //   DX = blen
+#ifndef GOEXPERIMENT_regabiargs
 //   R9 = address of output word (stores -1/0/1 here)
+#else
+// output:
+//   AX = output (-1/0/1)
+#endif
 TEXT cmpbody<>(SB),NOSPLIT,$0-0
 	CMPQ	SI, DI
 	JEQ	allsame
@@ -74,7 +100,9 @@ diff16:
 	CMPB	CX, (DI)(BX*1)
 	SETHI	AX
 	LEAQ	-1(AX*2), AX	// convert 1/0 to +1/-1
+#ifndef GOEXPERIMENT_regabiargs
 	MOVQ	AX, (R9)
+#endif
 	RET
 
 	// 0 through 16 bytes left, alen>=8, blen>=8
@@ -100,7 +128,9 @@ diff8:
 	SHRQ	CX, AX	// move a's bit to bottom
 	ANDQ	$1, AX	// mask bit
 	LEAQ	-1(AX*2), AX // 1/0 => +1/-1
+#ifndef GOEXPERIMENT_regabiargs
 	MOVQ	AX, (R9)
+#endif
 	RET
 
 	// 0-7 bytes in common
@@ -139,7 +169,9 @@ di_finish:
 	SHRQ	CX, SI	// move a's bit to bottom
 	ANDQ	$1, SI	// mask bit
 	LEAQ	-1(SI*2), AX // 1/0 => +1/-1
+#ifndef GOEXPERIMENT_regabiargs
 	MOVQ	AX, (R9)
+#endif
 	RET
 
 allsame:
@@ -149,7 +181,9 @@ allsame:
 	SETGT	AX	// 1 if alen > blen
 	SETEQ	CX	// 1 if alen == blen
 	LEAQ	-1(CX)(AX*2), AX	// 1,0,-1 result
+#ifndef GOEXPERIMENT_regabiargs
 	MOVQ	AX, (R9)
+#endif
 	RET
 
 	// this works for >= 64 bytes of data.

src/internal/bytealg/equal_amd64.s

@@ -6,7 +6,21 @@
 #include "textflag.h"
 
 // memequal(a, b unsafe.Pointer, size uintptr) bool
-TEXT runtime·memequal(SB),NOSPLIT,$0-25
+TEXT runtime·memequal<ABIInternal>(SB),NOSPLIT,$0-25
+#ifdef GOEXPERIMENT_regabiargs
+	// AX = a    (want in SI)
+	// BX = b    (want in DI)
+	// CX = size (want in BX)
+	CMPQ	AX, BX
+	JNE	neq
+	MOVQ	$1, AX	// return 1
+	RET
+neq:
+	MOVQ	AX, SI
+	MOVQ	BX, DI
+	MOVQ	CX, BX
+	JMP	memeqbody<>(SB)
+#else
 	MOVQ	a+0(FP), SI
 	MOVQ	b+8(FP), DI
 	CMPQ	SI, DI
@@ -17,9 +31,24 @@ TEXT runtime·memequal(SB),NOSPLIT,$0-25
 eq:
 	MOVB	$1, ret+24(FP)
 	RET
+#endif
 
 // memequal_varlen(a, b unsafe.Pointer) bool
-TEXT runtime·memequal_varlen(SB),NOSPLIT,$0-17
+TEXT runtime·memequal_varlen<ABIInternal>(SB),NOSPLIT,$0-17
+#ifdef GOEXPERIMENT_regabiargs
+	// AX = a       (want in SI)
+	// BX = b       (want in DI)
+	// 8(DX) = size (want in BX)
+	CMPQ	AX, BX
+	JNE	neq
+	MOVQ	$1, AX	// return 1
+	RET
+neq:
+	MOVQ	AX, SI
+	MOVQ	BX, DI
+	MOVQ	8(DX), BX    // compiler stores size at offset 8 in the closure
+	JMP	memeqbody<>(SB)
+#else
 	MOVQ	a+0(FP), SI
 	MOVQ	b+8(FP), DI
 	CMPQ	SI, DI
@@ -30,11 +59,18 @@ TEXT runtime·memequal_varlen(SB),NOSPLIT,$0-17
 eq:
 	MOVB	$1, ret+16(FP)
 	RET
+#endif
 
+// Input:
 //   a in SI
 //   b in DI
 //   count in BX
+#ifndef GOEXPERIMENT_regabiargs
 //   address of result byte in AX
+#else
+// Output:
+//   result in AX
+#endif
 TEXT memeqbody<>(SB),NOSPLIT,$0-0
 	CMPQ	BX, $8
 	JB	small
@@ -68,7 +104,11 @@ hugeloop:
 	SUBQ	$64, BX
 	CMPL	DX, $0xffff
 	JEQ	hugeloop
+#ifdef GOEXPERIMENT_regabiargs
+	XORQ	AX, AX	// return 0
+#else
 	MOVB	$0, (AX)
+#endif
 	RET
 
 	// 64 bytes at a time using ymm registers
@@ -89,7 +129,11 @@ hugeloop_avx2:
 	CMPL	DX, $0xffffffff
 	JEQ	hugeloop_avx2
 	VZEROUPPER
+#ifdef GOEXPERIMENT_regabiargs
+	XORQ	AX, AX	// return 0
+#else
 	MOVB	$0, (AX)
+#endif
 	RET
 
 bigloop_avx2:
@@ -106,7 +150,11 @@ bigloop:
 	SUBQ	$8, BX
 	CMPQ	CX, DX
 	JEQ	bigloop
+#ifdef GOEXPERIMENT_regabiargs
+	XORQ	AX, AX	// return 0
+#else
 	MOVB	$0, (AX)
+#endif
 	RET
 
 	// remaining 0-8 bytes
@@ -114,7 +162,11 @@ leftover:
 	MOVQ	-8(SI)(BX*1), CX
 	MOVQ	-8(DI)(BX*1), DX
 	CMPQ	CX, DX
+#ifdef GOEXPERIMENT_regabiargs
+	SETEQ	AX
+#else
 	SETEQ	(AX)
+#endif
 	RET
 
 small:
@@ -149,6 +201,10 @@ di_finish:
 	SUBQ	SI, DI
 	SHLQ	CX, DI
 equal:
+#ifdef GOEXPERIMENT_regabiargs
+	SETEQ	AX
+#else
 	SETEQ	(AX)
+#endif
 	RET