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PowerPC LE memset

From: Alan Modra <amodra at gmail dot com>
To: libc-alpha at sourceware dot org
Date: Fri, 9 Aug 2013 14:57:25 +0930
Subject: PowerPC LE memset
Well, not really an LE specific patch.  No #ifdef __LITTLE_ENDIAN__ here!

One of the things I noticed when looking at power7 timing is that rlwimi
is cracked and the two resulting insns have a register dependency.
That makes it a little slower than the equivalent rldimi.

	* sysdeps/powerpc/powerpc64/memset.S: Replace rlwimi with
        insrdi.  Formatting.
	* sysdeps/powerpc/powerpc64/power4/memset.S: Likewise.
	* sysdeps/powerpc/powerpc64/power6/memset.S: Likewise.
	* sysdeps/powerpc/powerpc64/power7/memset.S: Likewise.
	* sysdeps/powerpc/powerpc32/power4/memset.S: Likewise.
	* sysdeps/powerpc/powerpc32/power6/memset.S: Likewise.
	* sysdeps/powerpc/powerpc32/power7/memset.S: Likewise.

diff --git a/sysdeps/powerpc/powerpc64/memset.S b/sysdeps/powerpc/powerpc64/memset.S
index 6acf149..1027a59 100644
--- a/sysdeps/powerpc/powerpc64/memset.S
+++ b/sysdeps/powerpc/powerpc64/memset.S
@@ -55,14 +55,14 @@ L(_memset):
 
 /* Align to doubleword boundary.  */
 	cmpldi	cr5, rLEN, 31
-	rlwimi	rCHR, rCHR, 8, 16, 23 /* Replicate byte to halfword.  */
+	insrdi	rCHR, rCHR, 8, 48	/* Replicate byte to halfword.  */
 	beq+	L(aligned2)
 	mtcrf	0x01, rMEMP0
 	subfic	rALIGN, rALIGN, 8
 	cror	28,30,31		/* Detect odd word aligned.  */
 	add	rMEMP, rMEMP, rALIGN
 	sub	rLEN, rLEN, rALIGN
-	rlwimi	rCHR, rCHR, 16, 0, 15 /* Replicate halfword to word.  */
+	insrdi	rCHR, rCHR, 16, 32	/* Replicate halfword to word.  */
 	bt	29, L(g4)
 /* Process the even word of doubleword.  */
 	bf+	31, L(g2)
@@ -84,14 +84,14 @@ L(g0):
 
 /* Handle the case of size < 31.  */
 L(aligned2):
-	rlwimi	rCHR, rCHR, 16, 0, 15 /* Replicate halfword to word.  */
+	insrdi	rCHR, rCHR, 16, 32	/* Replicate halfword to word.  */
 L(aligned):
 	mtcrf	0x01, rLEN
 	ble	cr5, L(medium)
 /* Align to 32-byte boundary.  */
 	andi.	rALIGN, rMEMP, 0x18
 	subfic	rALIGN, rALIGN, 0x20
-	insrdi	rCHR,rCHR,32,0 /* Replicate word to double word. */
+	insrdi	rCHR, rCHR, 32, 0	/* Replicate word to double word. */
 	beq	L(caligned)
 	mtcrf	0x01, rALIGN
 	add	rMEMP, rMEMP, rALIGN
@@ -212,7 +212,7 @@ L(le4):
 /* Memset of 0-31 bytes.  */
 	.align 5
 L(medium):
-	insrdi	rCHR,rCHR,32,0 /* Replicate word to double word.  */
+	insrdi	rCHR, rCHR, 32, 0	/* Replicate word to double word.  */
 	cmpldi	cr1, rLEN, 16
 L(medium_tail2):
 	add	rMEMP, rMEMP, rLEN
diff --git a/sysdeps/powerpc/powerpc64/power4/memset.S b/sysdeps/powerpc/powerpc64/power4/memset.S
index dbecee8..ad0d381 100644
--- a/sysdeps/powerpc/powerpc64/power4/memset.S
+++ b/sysdeps/powerpc/powerpc64/power4/memset.S
@@ -50,14 +50,14 @@ L(_memset):
 
 /* Align to doubleword boundary.  */
 	cmpldi	cr5, rLEN, 31
-	rlwimi	rCHR, rCHR, 8, 16, 23 /* Replicate byte to halfword.  */
+	insrdi	rCHR, rCHR, 8, 48	/* Replicate byte to halfword.  */
 	beq+	L(aligned2)
 	mtcrf	0x01, rMEMP0
 	subfic	rALIGN, rALIGN, 8
 	cror	28,30,31		/* Detect odd word aligned.  */
 	add	rMEMP, rMEMP, rALIGN
 	sub	rLEN, rLEN, rALIGN
-	rlwimi	rCHR, rCHR, 16, 0, 15 /* Replicate halfword to word.  */
+	insrdi	rCHR, rCHR, 16, 32	/* Replicate halfword to word.  */
 	bt	29, L(g4)
 /* Process the even word of doubleword.  */
 	bf+	31, L(g2)
@@ -79,14 +79,14 @@ L(g0):
 
 /* Handle the case of size < 31.  */
 L(aligned2):
-	rlwimi	rCHR, rCHR, 16, 0, 15 /* Replicate halfword to word.  */
+	insrdi	rCHR, rCHR, 16, 32	/* Replicate halfword to word.  */
 L(aligned):
 	mtcrf	0x01, rLEN
 	ble	cr5, L(medium)
 /* Align to 32-byte boundary.  */
 	andi.	rALIGN, rMEMP, 0x18
 	subfic	rALIGN, rALIGN, 0x20
-	insrdi	rCHR,rCHR,32,0 /* Replicate word to double word. */
+	insrdi	rCHR, rCHR, 32, 0	/* Replicate word to double word. */
 	beq	L(caligned)
 	mtcrf	0x01, rALIGN
 	add	rMEMP, rMEMP, rALIGN
@@ -146,24 +146,24 @@ L(zloopstart):
 L(getCacheAligned):
 	cmpldi	cr1,rLEN,32
 	andi.	rTMP,rMEMP,127
-	blt		cr1,L(handletail32)
-	beq		L(cacheAligned)
+	blt	cr1,L(handletail32)
+	beq	L(cacheAligned)
 	addi	rMEMP,rMEMP,32
 	addi	rLEN,rLEN,-32
-	std		rCHR,-32(rMEMP)
-	std		rCHR,-24(rMEMP)
-	std		rCHR,-16(rMEMP)
-	std		rCHR,-8(rMEMP)
-	b		L(getCacheAligned)
+	std	rCHR,-32(rMEMP)
+	std	rCHR,-24(rMEMP)
+	std	rCHR,-16(rMEMP)
+	std	rCHR,-8(rMEMP)
+	b	L(getCacheAligned)
 
 /* Now we are aligned to the cache line and can use dcbz.  */
 L(cacheAligned):
 	cmpld	cr1,rLEN,rCLS
-	blt		cr1,L(handletail32)
+	blt	cr1,L(handletail32)
 	dcbz	0,rMEMP
 	subf	rLEN,rCLS,rLEN
-	add		rMEMP,rMEMP,rCLS
-	b		L(cacheAligned)
+	add	rMEMP,rMEMP,rCLS
+	b	L(cacheAligned)
 
 /* We are here because the cache line size was set and was not 32-bytes
    and the remainder (rLEN) is less than the actual cache line size.
@@ -200,7 +200,7 @@ L(le4):
 /* Memset of 0-31 bytes.  */
 	.align 5
 L(medium):
-	insrdi	rCHR,rCHR,32,0 /* Replicate word to double word.  */
+	insrdi	rCHR, rCHR, 32, 0	/* Replicate word to double word.  */
 	cmpldi	cr1, rLEN, 16
 L(medium_tail2):
 	add	rMEMP, rMEMP, rLEN
diff --git a/sysdeps/powerpc/powerpc64/power6/memset.S b/sysdeps/powerpc/powerpc64/power6/memset.S
index 541a45f..a3864cc 100644
--- a/sysdeps/powerpc/powerpc64/power6/memset.S
+++ b/sysdeps/powerpc/powerpc64/power6/memset.S
@@ -47,14 +47,14 @@ L(_memset):
 
 /* Align to doubleword boundary.  */
 	cmpldi	cr5, rLEN, 31
-	rlwimi	rCHR, rCHR, 8, 16, 23 /* Replicate byte to halfword.  */
+	insrdi	rCHR, rCHR, 8, 48	/* Replicate byte to halfword.  */
 	beq+	L(aligned2)
 	mtcrf	0x01, rMEMP0
 	subfic	rALIGN, rALIGN, 8
 	cror	28,30,31		/* Detect odd word aligned.  */
 	add	rMEMP, rMEMP, rALIGN
 	sub	rLEN, rLEN, rALIGN
-	rlwimi	rCHR, rCHR, 16, 0, 15 /* Replicate halfword to word.  */
+	insrdi	rCHR, rCHR, 16, 32	/* Replicate halfword to word.  */
 	bt	29, L(g4)
 /* Process the even word of doubleword.  */
 	bf+	31, L(g2)
@@ -76,14 +76,14 @@ L(g0):
 
 /* Handle the case of size < 31.  */
 L(aligned2):
-	rlwimi	rCHR, rCHR, 16, 0, 15 /* Replicate halfword to word.  */
+	insrdi	rCHR, rCHR, 16, 32	/* Replicate halfword to word.  */
 L(aligned):
 	mtcrf	0x01, rLEN
 	ble	cr5, L(medium)
 /* Align to 32-byte boundary.  */
 	andi.	rALIGN, rMEMP, 0x18
 	subfic	rALIGN, rALIGN, 0x20
-	insrdi	rCHR,rCHR,32,0 /* Replicate word to double word. */
+	insrdi	rCHR, rCHR, 32, 0	/* Replicate word to double word. */
 	beq	L(caligned)
 	mtcrf	0x01, rALIGN
 	add	rMEMP, rMEMP, rALIGN
@@ -344,7 +344,7 @@ L(le4):
 /* Memset of 0-31 bytes.  */
 	.align 5
 L(medium):
-	insrdi	rCHR,rCHR,32,0 /* Replicate word to double word.  */
+	insrdi	rCHR, rCHR, 32, 0	/* Replicate word to double word.  */
 	cmpldi	cr1, rLEN, 16
 L(medium_tail2):
 	add	rMEMP, rMEMP, rLEN
diff --git a/sysdeps/powerpc/powerpc64/power7/memset.S b/sysdeps/powerpc/powerpc64/power7/memset.S
index b24cfa1..8b081e8 100644
--- a/sysdeps/powerpc/powerpc64/power7/memset.S
+++ b/sysdeps/powerpc/powerpc64/power7/memset.S
@@ -32,8 +32,8 @@ L(_memset):
 	mr	10,3
 
 	/* Replicate byte to word.  */
-	rlwimi	4,4,8,16,23
-	rlwimi	4,4,16,0,15
+	insrdi	4,4,8,48
+	insrdi	4,4,16,32
 	ble	cr6,L(small)	/* If length <= 8, use short copy code.  */
 
 	neg	0,3
@@ -321,7 +321,7 @@ L(medium):
 	clrldi	0,0,62
 	beq	L(medium_aligned)
 
-	/* Force 4-bytes alignment for SRC.  */
+	/* Force 4-bytes alignment for DST.  */
 	mtocrf	0x01,0
 	subf	5,0,5
 1:	/* Copy 1 byte.  */
diff --git a/sysdeps/powerpc/powerpc32/power4/memset.S b/sysdeps/powerpc/powerpc32/power4/memset.S
index c2d288b..4fd9d8c 100644
--- a/sysdeps/powerpc/powerpc32/power4/memset.S
+++ b/sysdeps/powerpc/powerpc32/power4/memset.S
@@ -50,7 +50,7 @@ L(_memset):
 
 /* Align to word boundary.  */
 	cmplwi	cr5, rLEN, 31
-	rlwimi	rCHR, rCHR, 8, 16, 23 /* Replicate byte to halfword.  */
+	insrdi	rCHR, rCHR, 8, 48     /* Replicate byte to halfword.  */
 	beq+	L(aligned)
 	mtcrf	0x01, rMEMP0
 	subfic	rALIGN, rALIGN, 4
@@ -65,7 +65,7 @@ L(g0):
 /* Handle the case of size < 31.  */
 L(aligned):
 	mtcrf	0x01, rLEN
-	rlwimi	rCHR, rCHR, 16, 0, 15 /* Replicate halfword to word.  */
+	insrdi	rCHR, rCHR, 16, 32    /* Replicate halfword to word.  */
 	ble	cr5, L(medium)
 /* Align to 32-byte boundary.  */
 	andi.	rALIGN, rMEMP, 0x1C
diff --git a/sysdeps/powerpc/powerpc32/power6/memset.S b/sysdeps/powerpc/powerpc32/power6/memset.S
index ce06630..508d560 100644
--- a/sysdeps/powerpc/powerpc32/power6/memset.S
+++ b/sysdeps/powerpc/powerpc32/power6/memset.S
@@ -48,7 +48,7 @@ L(_memset):
 	ble-	cr1, L(small)
 /* Align to word boundary.  */
 	cmplwi	cr5, rLEN, 31
-	rlwimi	rCHR, rCHR, 8, 16, 23 /* Replicate byte to halfword.  */
+	insrdi	rCHR, rCHR, 8, 48	/* Replicate byte to halfword.  */
 	beq+	L(aligned)
 	mtcrf	0x01, rMEMP0
 	subfic	rALIGN, rALIGN, 4
@@ -64,7 +64,7 @@ L(g0):
 /* Handle the case of size < 31.  */
 L(aligned):
 	mtcrf	0x01, rLEN
-	rlwimi	rCHR, rCHR, 16, 0, 15 /* Replicate halfword to word.  */
+	insrdi	rCHR, rCHR, 16, 32	/* Replicate halfword to word.  */
 	ble	cr5, L(medium)
 /* Align to 32-byte boundary.  */
 	andi.	rALIGN, rMEMP, 0x1C
diff --git a/sysdeps/powerpc/powerpc32/power7/memset.S b/sysdeps/powerpc/powerpc32/power7/memset.S
index 360ea71..9322e9b 100644
--- a/sysdeps/powerpc/powerpc32/power7/memset.S
+++ b/sysdeps/powerpc/powerpc32/power7/memset.S
@@ -35,8 +35,8 @@ L(_memset):
 	cfi_offset(31,-8)
 
 	/* Replicate byte to word.  */
-	rlwimi	4,4,8,16,23
-	rlwimi	4,4,16,0,15
+	insrdi	4,4,8,48
+	insrdi	4,4,16,32
 
 	ble	cr6,L(small)	/* If length <= 8, use short copy code.  */
 

-- 
Alan Modra
Australia Development Lab, IBM
Follow-Ups:
- Re: PowerPC LE memset
  - From: Adhemerval Zanella
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