From: Jin Ma <jinma@linux.alibaba.com>
Date: Tue, 2 Jun 2026 13:07:00 +0000 (-0600)
Subject: [PATCH] RISC-V: Fix missing return in expand_vec_perm
X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=fe33ae48bf00ccb492bd65980899ca2bc421dabc;p=thirdparty%2Fgcc.git

[PATCH] RISC-V: Fix missing return in expand_vec_perm

In expand_vec_perm, the branch handling a selector that is a constant
duplicate (all indices identical) emits a VLMAX vrgather and is then
meant to be done.  The missing return let control fall through into the
generic modulo-index handling below, which recomputes and overwrites
the target with another gather sequence.

Add the return so the duplicate path stops after the gather.

No test case is added: without the return the first gather is a dead
store to the target that the generic path immediately overwrites, so it
is removed by later RTL dead-store elimination and the final assembly is
identical with and without the fix.  No test can therefore observe the
change.

gcc/ChangeLog:

	* config/riscv/riscv-v.cc (expand_vec_perm): Add missing return
	after emit_vlmax_gather_insn.
---

diff --git a/gcc/config/riscv/riscv-v.cc b/gcc/config/riscv/riscv-v.cc
index b7dd1c8279a..2f1d1be50d6 100644
--- a/gcc/config/riscv/riscv-v.cc
+++ b/gcc/config/riscv/riscv-v.cc
@@ -3320,6 +3320,7 @@ expand_vec_perm (rtx target, rtx op0, rtx op1, rtx sel)
 	  op = op1;
 	}
       emit_vlmax_gather_insn (target, op, sel);
+      return;
     }
 
   /* Note: vec_perm indices are supposed to wrap when they go beyond the