[gcc r14-8442] RISC-V: Fix incorrect LCM delete bug [VSETVL PASS]

[gcc r14-8442] RISC-V: Fix incorrect LCM delete bug [VSETVL PASS]

[Pan Li]

https://gcc.gnu.org/g:d40b3c1e439db05c835b6bd4fd5bba58fda71dd6

commit r14-8442-gd40b3c1e439db05c835b6bd4fd5bba58fda71dd6
Author: Juzhe-Zhong <juzhe.zhong@rivai.ai>
Date:   Fri Jan 26 14:46:21 2024 +0800

    RISC-V: Fix incorrect LCM delete bug [VSETVL PASS]
    
    This patch fixes the recent noticed bug in RV32 glibc.
    
    We incorrectly deleted a vsetvl:
    
            ...
            and     a4,a4,a3
            vmv.v.i v1,0                 ---> Missed vsetvl cause illegal instruction report.
            vse8.v  v1,0(a5)
    
    The root cause the laterin in LCM is incorrect.
    
          BB 358:
            avloc: n_bits = 2, set = {}
            kill: n_bits = 2, set = {}
            antloc: n_bits = 2, set = {}
            transp: n_bits = 2, set = {}
            avin: n_bits = 2, set = {}
            avout: n_bits = 2, set = {}
            del: n_bits = 2, set = {}
    
    cause LCM let BB 360 delete the vsetvl:
    
          BB 360:
            avloc: n_bits = 2, set = {}
            kill: n_bits = 2, set = {}
            antloc: n_bits = 2, set = {}
            transp: n_bits = 2, set = {0 1 }
            avin: n_bits = 2, set = {}
            avout: n_bits = 2, set = {}
            del: n_bits = 2, set = {1}
    
    Also, remove unknown vsetvl info into local computation since it is unnecessary.
    
    Tested on both RV32/RV64 no regression.
    
            PR target/113469
    
    gcc/ChangeLog:
    
            * config/riscv/riscv-vsetvl.cc (pre_vsetvl::compute_lcm_local_properties): Fix bug.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.target/riscv/rvv/autovec/pr113469.c: New test.

Diff:
---
 gcc/config/riscv/riscv-vsetvl.cc                   | 19 ++++----
 .../gcc.target/riscv/rvv/autovec/pr113469.c        | 54 ++++++++++++++++++++++
 2 files changed, 64 insertions(+), 9 deletions(-)

diff --git a/gcc/config/riscv/riscv-vsetvl.cc b/gcc/config/riscv/riscv-vsetvl.cc
index da258b964fcb..1a398f025963 100644
--- a/gcc/config/riscv/riscv-vsetvl.cc
+++ b/gcc/config/riscv/riscv-vsetvl.cc
@@ -2543,8 +2543,10 @@ pre_vsetvl::compute_lcm_local_properties ()
       vsetvl_info &header_info = block_info.get_entry_info ();
       vsetvl_info &footer_info = block_info.get_exit_info ();
       gcc_assert (footer_info.valid_p () || footer_info.unknown_p ());
-      add_expr (m_exprs, header_info);
-      add_expr (m_exprs, footer_info);
+      if (header_info.valid_p ())
+	add_expr (m_exprs, header_info);
+      if (footer_info.valid_p ())
+	add_expr (m_exprs, footer_info);
     }
 
   int num_exprs = m_exprs.length ();
@@ -2699,13 +2701,6 @@ pre_vsetvl::compute_lcm_local_properties ()
 	  }
     }
 
-  for (const bb_info *bb : crtl->ssa->bbs ())
-    {
-      unsigned bb_index = bb->index ();
-      bitmap_ior (m_kill[bb_index], m_transp[bb_index], m_avloc[bb_index]);
-      bitmap_not (m_kill[bb_index], m_kill[bb_index]);
-    }
-
   for (const bb_info *bb : crtl->ssa->bbs ())
     {
       unsigned bb_index = bb->index ();
@@ -2714,6 +2709,12 @@ pre_vsetvl::compute_lcm_local_properties ()
 	  bitmap_clear (m_antloc[bb_index]);
 	  bitmap_clear (m_transp[bb_index]);
 	}
+      /* Compute ae_kill for each basic block using:
+
+	 ~(TRANSP | COMP)
+      */
+      bitmap_ior (m_kill[bb_index], m_transp[bb_index], m_avloc[bb_index]);
+      bitmap_not (m_kill[bb_index], m_kill[bb_index]);
     }
 }
 
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr113469.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr113469.c
new file mode 100644
index 000000000000..d1c118c02d6e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr113469.c
@@ -0,0 +1,54 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv32gcv -mabi=ilp32d -O3 -fno-vect-cost-model" } */
+
+struct a {
+ int b;
+ int c : 1;
+ int : 1;
+} d();
+typedef struct
+{
+ int e;
+ struct {
+   int f;
+ };
+} g;
+int i;
+char k, l, n;
+void *m;
+char *o;
+void h();
+char *j();
+void p(int buf, __builtin_va_list ab, int q) {
+ do {
+   void *r[] = {&&s, &&t, &&u, &&v, &&w};
+   int c;
+   goto *m;
+ s:
+   c = 1;
+   while (1) {
+   t:
+   u:
+   ae:
+     void *af = __builtin_va_arg(ab, void *);
+     h(p);
+     o = j(i);
+     if (o == 0)
+       goto ae;
+     l = 'S';
+     break;
+   v:
+     g ah;
+     __builtin_memset(&ah, '\0', sizeof(g));
+     h(n, __builtin_va_arg(ab, int), &ah);
+     break;
+   w:
+     if (__builtin_expect(q, 0))
+       c = 0;
+     struct a ai = {'S', c};
+     d(buf, ai, af);
+   }
+ } while (k);
+}
+
+/* { dg-final { scan-assembler-times {vsetivli\tzero,\s*4,\s*e8,\s*mf4,\s*t[au],\s*m[au]} 2 } } */