From aed0611fb8bacef429fdc50725c24c5226484351 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Fri, 2 Feb 2024 06:16:33 +0530
Subject: [PATCH] Avoid double trailing RET

---
 tools/simdstring/generate.go | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/tools/simdstring/generate.go b/tools/simdstring/generate.go
index fdbd2bf80..5ecca2b60 100644
--- a/tools/simdstring/generate.go
+++ b/tools/simdstring/generate.go
@@ -1052,7 +1052,21 @@ func (s *Function) OutputASM(w io.Writer) {
 		fmt.Fprintln(w, "\tVZEROUPPER // zero upper bits of AVX registers to avoid dependencies when switching between SSE and AVX code")
 	}
 
-	s.Return()
+	has_trailing_return := false
+	for _, i := range s.Instructions {
+		if len(i) == 0 {
+			continue
+		}
+		if strings.HasPrefix(i, "\tRET ") {
+			has_trailing_return = true
+		} else {
+			has_trailing_return = false
+		}
+	}
+
+	if !has_trailing_return {
+		s.Return()
+	}
 	for _, i := range s.Instructions {
 		fmt.Fprintln(w, i)
 	}