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authorKatie Hockman <katie@golang.org>2020-12-14 10:03:05 -0500
committerKatie Hockman <katie@golang.org>2020-12-14 10:06:13 -0500
commit0345ede87ee12698988973884cfc0fd3d499dffd (patch)
tree7123cff141ee5661208d2f5f437b8f5252ac7f6a /src/cmd/internal/obj/arm64/doc.go
parent4651d6b267818b0e0d128a5443289717c4bb8cbc (diff)
parent0a02371b0576964e81c3b40d328db9a3ef3b031b (diff)
downloadgo-0345ede87ee12698988973884cfc0fd3d499dffd.tar.xz
[dev.fuzz] all: merge master into dev.fuzz
Change-Id: I5d8c8329ccc9d747bd81ade6b1cb7cb8ae2e94b2
Diffstat (limited to 'src/cmd/internal/obj/arm64/doc.go')
-rw-r--r--src/cmd/internal/obj/arm64/doc.go10
1 files changed, 10 insertions, 0 deletions
diff --git a/src/cmd/internal/obj/arm64/doc.go b/src/cmd/internal/obj/arm64/doc.go
index 7515217544..efd4577f56 100644
--- a/src/cmd/internal/obj/arm64/doc.go
+++ b/src/cmd/internal/obj/arm64/doc.go
@@ -86,6 +86,16 @@ In the following example, PCALIGN at the entry of the function Add will align it
MOVD $1, R1
RET
+7. Move large constants to vector registers.
+
+Go asm uses VMOVQ/VMOVD/VMOVS to move 128-bit, 64-bit and 32-bit constants into vector registers, respectively.
+And for a 128-bit interger, it take two 64-bit operands, for the high and low parts separately.
+
+ Examples:
+ VMOVS $0x11223344, V0
+ VMOVD $0x1122334455667788, V1
+ VMOVQ $0x1122334455667788, $8877665544332211, V2 // V2=0x11223344556677888877665544332211
+
Special Cases.
(1) umov is written as VMOV.