From f0e9dc09752cc2f03fcedff458660ab2276bcf8d Mon Sep 17 00:00:00 2001
From: Junyang Shao <shaojunyang@google.com>
Date: Thu, 17 Jul 2025 22:23:15 +0000
Subject: [PATCH] [dev.simd] cmd/compile: fix opLen(2|3)Imm8_2I intrinsic
 function

This function reads the const from the wrong arg, this CL fixes it.

Change-Id: Icd38977a35f0df9064efb290fa6390453d6b9e5b
Reviewed-on: https://go-review.googlesource.com/c/go/+/688595
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
---
 src/cmd/compile/internal/ssagen/intrinsics.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/cmd/compile/internal/ssagen/intrinsics.go b/src/cmd/compile/internal/ssagen/intrinsics.go
index 337f0b86e6..5415143ec3 100644
--- a/src/cmd/compile/internal/ssagen/intrinsics.go
+++ b/src/cmd/compile/internal/ssagen/intrinsics.go
@@ -1722,7 +1722,7 @@ func opLen3Imm8(op ssa.Op, t *types.Type, offset int) func(s *state, n *ir.CallE
 
 func opLen2Imm8_2I(op ssa.Op, t *types.Type, offset int) func(s *state, n *ir.CallExpr, args []*ssa.Value) *ssa.Value {
 	return func(s *state, n *ir.CallExpr, args []*ssa.Value) *ssa.Value {
-		if args[1].Op == ssa.OpConst8 {
+		if args[2].Op == ssa.OpConst8 {
 			return s.newValue2I(op, t, args[2].AuxInt<<int64(offset), args[0], args[1])
 		}
 		plainPanicSimdImm(s)
@@ -1736,7 +1736,7 @@ func opLen2Imm8_2I(op ssa.Op, t *types.Type, offset int) func(s *state, n *ir.Ca
 
 func opLen3Imm8_2I(op ssa.Op, t *types.Type, offset int) func(s *state, n *ir.CallExpr, args []*ssa.Value) *ssa.Value {
 	return func(s *state, n *ir.CallExpr, args []*ssa.Value) *ssa.Value {
-		if args[1].Op == ssa.OpConst8 {
+		if args[2].Op == ssa.OpConst8 {
 			return s.newValue3I(op, t, args[2].AuxInt<<int64(offset), args[0], args[1], args[3])
 		}
 		plainPanicSimdImm(s)
-- 
2.52.0