From: Keith Randall <khr@golang.org>
Date: Sun, 10 Apr 2022 16:12:43 +0000 (-0700)
Subject: cmd/asm: fix MOVK when constant has high bit set
X-Git-Tag: go1.19beta1~724
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=a6f6932b3ee87d9607ce246228e23f9a08dacc31;p=gostls13.git

cmd/asm: fix MOVK when constant has high bit set

Fixes #52261

Change-Id: I1dc4c19c95a91f9e1e99d1e74afeb69f5bf8a979
Reviewed-on: https://go-review.googlesource.com/c/go/+/399455
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Eric Fang <eric.fang@arm.com>
---

diff --git a/src/cmd/internal/obj/arm64/asm7.go b/src/cmd/internal/obj/arm64/asm7.go
index 72c4cd48ed..57d4e7a8d3 100644
--- a/src/cmd/internal/obj/arm64/asm7.go
+++ b/src/cmd/internal/obj/arm64/asm7.go
@@ -3977,7 +3977,7 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		if (o1&S64) == 0 && s >= 2 {
 			c.ctxt.Diag("illegal bit position\n%v", p)
 		}
-		if ((d >> uint(s*16)) >> 16) != 0 {
+		if ((uint64(d) >> uint(s*16)) >> 16) != 0 {
 			c.ctxt.Diag("requires uimm16\n%v", p)
 		}
 		rt := int(p.To.Reg)
diff --git a/src/cmd/internal/obj/arm64/asm_arm64_test.go b/src/cmd/internal/obj/arm64/asm_arm64_test.go
index c6a00f5b94..f468b6b0fe 100644
--- a/src/cmd/internal/obj/arm64/asm_arm64_test.go
+++ b/src/cmd/internal/obj/arm64/asm_arm64_test.go
@@ -160,3 +160,14 @@ func TestVMOVQ(t *testing.T) {
 		t.Errorf("TestVMOVQ got: a=0x%x, b=0x%x, want: a=0x7040201008040201, b=0x3040201008040201", a, b)
 	}
 }
+
+func testmovk() uint64
+
+// TestMOVK makes sure MOVK with a very large constant works. See issue 52261.
+func TestMOVK(t *testing.T) {
+	x := testmovk()
+	want := uint64(40000 << 48)
+	if x != want {
+		t.Errorf("TestMOVK got %x want %x\n", x, want)
+	}
+}
diff --git a/src/cmd/internal/obj/arm64/asm_arm64_test.s b/src/cmd/internal/obj/arm64/asm_arm64_test.s
index 9d337a4fd1..f85433c6e3 100644
--- a/src/cmd/internal/obj/arm64/asm_arm64_test.s
+++ b/src/cmd/internal/obj/arm64/asm_arm64_test.s
@@ -12,3 +12,10 @@ TEXT ·testvmovq(SB), NOSPLIT, $0-16
 	MOVD    R0, r1+0(FP)
 	MOVD    R1, r2+8(FP)
 	RET
+
+// testmovk() uint64
+TEXT ·testmovk(SB), NOSPLIT, $0-8
+	MOVD	$0, R0
+	MOVK	$(40000<<48), R0
+	MOVD	R0, ret+0(FP)
+	RET