From: Ju-Zhe Zhong <juzhe.zhong@rivai.ai>
Date: Wed, 18 Jan 2023 02:50:14 +0000 (+0800)
Subject: RISC-V: Change VSETVL PASS always call split_all_insns
X-Git-Tag: basepoints/gcc-14~1779
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ca8fb0096713a8477614ef874f16ba5bf16c48bc;p=thirdparty%2Fgcc.git

RISC-V: Change VSETVL PASS always call split_all_insns

Since LCM will destroy CFG, we are going to reorder the location of VSETVL PASS
at least before bbro (block-reorder PASS) which is before split3 PASS. We need
to call it in VSETVL PASS to get final RVV instructions patterns.

gcc/ChangeLog:

	* config/riscv/riscv-vsetvl.cc (pass_vsetvl::execute): Always call split_all_insns.
---

diff --git a/gcc/config/riscv/riscv-vsetvl.cc b/gcc/config/riscv/riscv-vsetvl.cc
index e4bc3d2b3536..8b3fd33f5586 100644
--- a/gcc/config/riscv/riscv-vsetvl.cc
+++ b/gcc/config/riscv/riscv-vsetvl.cc
@@ -3086,12 +3086,10 @@ pass_vsetvl::execute (function *)
   if (n_basic_blocks_for_fn (cfun) <= 0)
     return 0;
 
-  /* The reason we have this since we didn't finish splitting yet
-     when optimize == 0. In this case, we should conservatively
-     split all instructions here to make sure we don't miss any
-     RVV instruction.  */
-  if (!optimize)
-    split_all_insns ();
+  /* The RVV instruction may change after split which is not a stable
+     instruction. We need to split it here to avoid potential issue
+     since the VSETVL PASS is insert before split PASS.  */
+  split_all_insns ();
 
   /* Early return for there is no vector instructions.  */
   if (!has_vector_insn (cfun))