[gcc r14-4173] RISC-V: Fix Demand comparison bug[VSETVL PASS]

[gcc r14-4173] RISC-V: Fix Demand comparison bug[VSETVL PASS]

[Lehua Ding]

https://gcc.gnu.org/g:c3d2b6bc913803d3eccacb9e354f37eef1cee212

commit r14-4173-gc3d2b6bc913803d3eccacb9e354f37eef1cee212
Author: Juzhe-Zhong <juzhe.zhong@rivai.ai>
Date:   Wed Sep 20 16:07:49 2023 +0800

    RISC-V: Fix Demand comparison bug[VSETVL PASS]
    
    This bug is exposed when we support VLS integer conversion patterns.
    
    FAIL: c-c++-common/torture/pr53505.c execution.
    
    This is because incorrect vsetvl elimination by Phase 4:
    
       10318:       0d207057                vsetvli zero,zero,e32,m4,ta,ma
       1031c:       5e003e57                vmv.v.i v28,0
       .....:       ........                missed e8,m1 vsetvl
       10320:       7b07b057                vmsgtu.vi       v0,v16,15
       10324:       03083157                vadd.vi v2,v16,-16
    
    Regression on release version GCC no surprise difference.
    
    Committed.
    
    gcc/ChangeLog:
    
            * config/riscv/riscv-vsetvl.cc (vector_insn_info::operator==): Fix bug.

Diff:
---
 gcc/config/riscv/riscv-vsetvl.cc | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/gcc/config/riscv/riscv-vsetvl.cc b/gcc/config/riscv/riscv-vsetvl.cc
index df980b6770e..e0f61148ef3 100644
--- a/gcc/config/riscv/riscv-vsetvl.cc
+++ b/gcc/config/riscv/riscv-vsetvl.cc
@@ -1799,10 +1799,11 @@ vector_insn_info::operator== (const vector_insn_info &other) const
     if (m_demands[i] != other.demand_p ((enum demand_type) i))
       return false;
 
-  if (vector_config_insn_p (m_insn->rtl ())
-      || vector_config_insn_p (other.get_insn ()->rtl ()))
-    if (m_insn != other.get_insn ())
-      return false;
+  /* We should consider different INSN demands as different
+     expression.  Otherwise, we will be doing incorrect vsetvl
+     elimination.  */
+  if (m_insn != other.get_insn ())
+    return false;
 
   if (!same_avl_p (other))
     return false;