From 8ab42a945aef7c09189a60263c4450a65bc00a47 Mon Sep 17 00:00:00 2001
From: fanzha02 <fannie.zhang@arm.com>
Date: Tue, 3 Nov 2020 17:31:04 +0800
Subject: cmd/compile: merge ANDconst and UBFX into UBFX on arm64

Add a new rewrite rule to merge ANDconst and UBFX into
UBFX.

Add test cases.

Change-Id: I24d6442d0c956d7ce092c3a3858d4a3a41771670
Reviewed-on: https://go-review.googlesource.com/c/go/+/377054
Trust: Fannie Zhang <Fannie.Zhang@arm.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
---
 test/codegen/bitfield.go | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'test/codegen')

diff --git a/test/codegen/bitfield.go b/test/codegen/bitfield.go
index 8327da6cf8..11f31ecf25 100644
--- a/test/codegen/bitfield.go
+++ b/test/codegen/bitfield.go
@@ -321,6 +321,12 @@ func ubfx15(x uint64) bool {
 	return false
 }
 
+// merge ANDconst and ubfx into ubfx
+func ubfx16(x uint64) uint64 {
+	// arm64:"UBFX\t[$]4, R[0-9]+, [$]6",-"AND\t[$]63"
+	return ((x >> 3) & 0xfff) >> 1 & 0x3f
+}
+
 // Check that we don't emit comparisons for constant shifts.
 //go:nosplit
 func shift_no_cmp(x int) int {
-- 
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