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Re: [PATCH 2/3] sparc: assembly version of memmove for ultra1+


I'll clean up the nits and double check for any other missing delay slot spaces.
I expect I'll have it ready for resubmission later today.
- patrick

On 9/27/2017 3:40 PM, Sam Ravnborg wrote:
Hi Patrick.

Nitpick below.

	Sam

+
+.Ls2alg:
+	lduh	[%o1], %o3	/* know src is 2 byte aligned  */
+	inc	2, %o1
+	srl	%o3, 8, %o4
+	stb	%o4, [%o0]	/* have to do bytes,  */
+	stb	%o3, [%o0 + 1]	/* don't know dst alingment  */
+	inc	2, %o0
+	dec	2, %o2
+
+.Laldst:
+	andcc	%o0, 3, %o5	/* align the destination address  */
.Lald:	bz,pn	%icc, .Lw4cp
Label on own line would make patches more readable.
But src looks OK.

+	 cmp	%o5, 2
+	bz,pn	%icc, .Lw2cp
+	 cmp	%o5, 3
+.Lw3cp:
+	lduw	[%o1], %o4
+	inc	4, %o1
+	srl	%o4, 24, %o5
+	stb	%o5, [%o0]
+	bne,pt	%icc, .Lw1cp
+	 inc	%o0
+	dec	1, %o2
+	andn	%o2, 3, %o3	/* i3 is aligned word count  */
+	dec	4, %o3		/* avoid reading beyond tail of src  */
+	sub	%o1, %o0, %o1	/* i1 gets the difference  */
+
+1:	sll	%o4, 8, %g1	/* save residual bytes  */
+	lduw	[%o1+%o0], %o4
+	deccc	4, %o3
+	srl	%o4, 24, %o5	/* merge with residual  */
+	or	%o5, %g1, %g1
+	st	%g1, [%o0]
+	bnz,pt	%XCC, 1b
+	 inc	4, %o0
+	sub	%o1, 3, %o1	/* used one byte of last word read  */
+	and	%o2, 3, %o2
+	b	7f
+	 inc	4, %o2
+
+.Lw1cp:
+	srl	%o4, 8, %o5
+	sth	%o5, [%o0]
+	inc	2, %o0
+	dec	3, %o2
+	andn	%o2, 3, %o3
+	dec	4, %o3		/* avoid reading beyond tail of src  */
+	sub	%o1, %o0, %o1	/* i1 gets the difference  */
+
+2:	sll	%o4, 24, %g1	/* save residual bytes  */
+	lduw	[%o1+%o0], %o4
+	deccc	4, %o3
+	srl	%o4, 8, %o5	/* merge with residual  */
+	or	%o5, %g1, %g1
+	st	%g1, [%o0]
+	bnz,pt	%XCC, 2b
+	 inc	4, %o0
+	sub	%o1, 1, %o1	/* used three bytes of last word read  */
+	and	%o2, 3, %o2
+	b	7f
+	inc	4, %o2
Delay slot - indent instruction with one space.

+
+.Lw2cp:
+	lduw	[%o1], %o4
+	inc	4, %o1
+	srl	%o4, 16, %o5
+	sth	%o5, [%o0]
+	inc	2, %o0
+	dec	2, %o2
+	andn	%o2, 3, %o3	/* i3 is aligned word count  */
+	dec	4, %o3		/* avoid reading beyond tail of src  */
+	sub	%o1, %o0, %o1	/* i1 gets the difference  */
+
+3:	sll	%o4, 16, %g1	/* save residual bytes  */
+	lduw	[%o1+%o0], %o4
+	deccc	4, %o3
+	srl	%o4, 16, %o5	/* merge with residual  */
+	or	%o5, %g1, %g1
+	st	%g1, [%o0]
+	bnz,pt	%XCC, 3b
+	 inc	4, %o0
+	sub	%o1, 2, %o1	/* used two bytes of last word read  */
+	and	%o2, 3, %o2
+	b	7f
+	 inc	4, %o2
+
+.Lw4cp:
+	andn	%o2, 3, %o3	/* i3 is aligned word count  */
+	sub	%o1, %o0, %o1	/* i1 gets the difference  */
+
+1:	lduw	[%o1+%o0], %o4	/* read from address  */
+	deccc	4, %o3		/* decrement count  */
+	st	%o4, [%o0]	/* write at destination address  */
+	bg,pt	%XCC, 1b
+	 inc	4, %o0		/* increment to address  */
+	b	7f
+	 and	%o2, 3, %o2	/* number of leftover bytes, if any  */
+
+/*
+ * differenced byte copy, works with any alignment
+ */
+.Ldbytecp:
+	b	7f
+	 sub	%o1, %o0, %o1	/* i1 gets the difference  */
+
+4:	stb	%o4, [%o0]	/* write to address  */
+	inc	%o0		/* inc to address  */
+7:	deccc	%o2		/* decrement count  */
+	bge,a	%XCC, 4b	/* loop till done  */
+	 ldub	[%o1+%o0], %o4	/* read from address  */
+	retl
+	 mov	%g2, %o0	/* return pointer to destination  */
+
+/*
+ * an overlapped copy that must be done "backwards"
+ */
+.Lovbc:
+	add	%o1, %o2, %o1	/* get to end of source space  */
+	add	%o0, %o2, %o0	/* get to end of destination space  */
+	sub	%o1, %o0, %o1	/* i1 gets the difference  */
+
+5:	dec	%o0		/* decrement to address  */
+	ldub	[%o1+%o0], %o3	/* read a byte  */
+	deccc	%o2		/* decrement count  */
+	bg,pt	%XCC, 5b 	/* loop until done  */
+	 stb	%o3, [%o0]	/* write byte  */
+	retl
+	 mov	%g2, %o0	/* return pointer to destination  */
+END(memmove)
+
+libc_hidden_builtin_def (memmove)


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