[glibc] aarch64: Add back non-temporal load/stores from oryon-1's memcpy

Andrew Pinski pinskia@sourceware.org
Tue Apr 15 19:07:21 GMT 2025


https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=0e1aa5db738ac7c73599a3e7f1a0b70b99f99e0a

commit 0e1aa5db738ac7c73599a3e7f1a0b70b99f99e0a
Author: Andrew Pinski <quic_apinski@quicinc.com>
Date:   Fri Feb 21 15:10:18 2025 -0800

    aarch64: Add back non-temporal load/stores from oryon-1's memcpy
    
    I misunderstood the recommendation from the hardware team about non-temporal
    load/stores. It is still recommended to use them in memcpy for large sizes. It
    was not recommended for their use with device memory and memcpy is already
    not valid to be use with device memory.
    
    This reverts commit eb5eeb47403e0a91de834868e501b4d62b8d2cb9.
    Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
    Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

Diff:
---
 sysdeps/aarch64/multiarch/memcpy_oryon1.S | 40 +++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/sysdeps/aarch64/multiarch/memcpy_oryon1.S b/sysdeps/aarch64/multiarch/memcpy_oryon1.S
index e86d8b04f5..cc267db53c 100644
--- a/sysdeps/aarch64/multiarch/memcpy_oryon1.S
+++ b/sysdeps/aarch64/multiarch/memcpy_oryon1.S
@@ -152,6 +152,46 @@ L(copy96):
 	.p2align 6
 L(copy_long):
 
+	/* On oryon1 cores, large memcpy's are helped by using ldnp/stnp.
+	   This loop is identical to the one below it but using ldnp/stnp
+	   instructions.  For loops that are less than 32768 bytes,
+	   the ldnp/stnp instructions will not help and will cause a slow
+	   down so only use the ldnp/stnp loop for the largest sizes.  */
+
+	cmp	count, #32768
+	b.lo	L(copy_long_without_nontemp)
+	and	tmp1, dstin, 15
+	bic	dst, dstin, 15
+	ldnp	D_l, D_h, [src]
+	sub	src, src, tmp1
+	add	count, count, tmp1	/* Count is now 16 too large.  */
+	ldnp	A_l, A_h, [src, 16]
+	stnp	D_l, D_h, [dstin]
+	ldnp	B_l, B_h, [src, 32]
+	ldnp	C_l, C_h, [src, 48]
+	ldnp	D_l, D_h, [src, 64]
+	add	src, src, #64
+	subs	count, count, 128 + 16	/* Test and readjust count.  */
+
+L(nontemp_loop64):
+	tbz	src, #6, 1f
+1:
+	stnp	A_l, A_h, [dst, 16]
+	ldnp	A_l, A_h, [src, 16]
+	stnp	B_l, B_h, [dst, 32]
+	ldnp	B_l, B_h, [src, 32]
+	stnp	C_l, C_h, [dst, 48]
+	ldnp	C_l, C_h, [src, 48]
+	stnp	D_l, D_h, [dst, 64]
+	ldnp	D_l, D_h, [src, 64]
+	add	src, src, #64
+	add	dst, dst, #64
+	subs	count, count, 64
+	b.hi	L(nontemp_loop64)
+	b	L(last64)
+
+L(copy_long_without_nontemp):
+
 	and	tmp1, dstin, 15
 	bic	dst, dstin, 15
 	ldp	D_l, D_h, [src]


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