big/arith: assembly routines for 386 long shifts (2nd round)

R=rsc
CC=golang-dev
https://golang.org/cl/986044

diff --git a/src/pkg/big/arith_386.s b/src/pkg/big/arith_386.s
index 4ccf217ed2a98af4bd9ca8d783149ca10c17c8ea..22fde9ccbf114c784bfc5d9b417c88c0fcd9ce9a 100644 (file)
--- a/src/pkg/big/arith_386.s
+++ b/src/pkg/big/arith_386.s
@@ -101,24 +101,24 @@ E4:       CMPL BX, BP             // i < n
 
 // func shlVW(z, x *Word, s Word, n int) (c Word)
 TEXT ·shlVW(SB),7,$0
-       NOP
-       JMP ·shlVW_g(SB)       // TODO(gri) remove once code below works
-
        MOVL z+0(FP), DI
        MOVL x+4(FP), SI
        MOVL s+8(FP), CX
-       MOVL n+12(FP), BP
+       MOVL n+12(FP), BX
+       LEAL (DI)(BX*4), DI
+       LEAL (SI)(BX*4), SI
+       NEGL BX                 // i = -n
        MOVL $0, AX             // c = 0
-       MOVL $0, BX             // i = 0
        JMP E8
 
-L8:    MOVL (SI)(BX*8), DX
+L8:    MOVL (SI)(BX*4), DX
+       MOVL DX, BP
        SHLL CX, DX:AX
-       MOVL DX, (DI)(BX*8)
-       MOVL (SI)(BX*8), AX     // reload (not enough regs to save original DX)
+       MOVL DX, (DI)(BX*4)
+       MOVL BP, AX
        ADDL $1, BX             // i++
 
-E8:    CMPL BX, BP             // i < n
+E8:    CMPL BX, $0             // i < 0
        JL L8
 
        MOVL $0, DX
@@ -129,9 +129,6 @@ E8: CMPL BX, BP             // i < n
 
 // func shrVW(z, x *Word, s Word, n int) (c Word)
 TEXT ·shrVW(SB),7,$0
-       NOP
-       JMP ·shrVW_g(SB)       // TODO(gri) remove once code below works
-
        MOVL z+0(FP), DI
        MOVL x+4(FP), SI
        MOVL s+8(FP), CX
@@ -139,10 +136,10 @@ TEXT ·shrVW(SB),7,$0
        MOVL $0, AX             // c = 0
        JMP E9
 
-L9:    MOVL (SI)(BX*8), DX
+L9:    MOVL (SI)(BX*4), DX
        MOVL DX, BP
        SHRL CX, DX:AX
-       MOVL DX, (DI)(BX*8)
+       MOVL DX, (DI)(BX*4)
        MOVL BP, AX
 
 E9:    SUBL $1, BX             // i--
@@ -161,9 +158,9 @@ TEXT ·mulAddVWW(SB),7,$0
        MOVL y+8(FP), BP
        MOVL r+12(FP), CX       // c = r
        MOVL n+16(FP), BX
-       LEAL    (SI)(BX*4), SI
-       LEAL    (DI)(BX*4), DI
-       NEGL BX  // i = -n
+       LEAL (DI)(BX*4), DI
+       LEAL (SI)(BX*4), SI
+       NEGL BX                 // i = -n
        JMP E5
 
 L5:    MOVL (SI)(BX*4), AX
@@ -187,8 +184,8 @@ TEXT ·addMulVVW(SB),7,$0
        MOVL x+4(FP), SI
        MOVL y+8(FP), BP
        MOVL n+12(FP), BX
-       LEAL    (SI)(BX*4), SI
-       LEAL    (DI)(BX*4), DI
+       LEAL (DI)(BX*4), DI
+       LEAL (SI)(BX*4), SI
        NEGL BX                 // i = -n
        MOVL $0, CX             // c = 0
        JMP E6