[gcc r14-6490] RISC-V: Postpone full available optimization [VSETVL PASS]

[Pan Li]

https://gcc.gnu.org/g:ef21ae5c45f3b79a36fadc1cb5723c095e2965ad

commit r14-6490-gef21ae5c45f3b79a36fadc1cb5723c095e2965ad
Author: Juzhe-Zhong <juzhe.zhong@rivai.ai>
Date:   Wed Dec 13 13:48:11 2023 +0800

    RISC-V: Postpone full available optimization [VSETVL PASS]
    
    Fix VSETVL BUG that AVL is polluted
    
    .L15:
            li      a3,9
            lui     a4,%hi(s)
            sw      a3,%lo(j)(t2)
            sh      a5,%lo(s)(a4) <--a4 is hold the address of s
            beq     t0,zero,.L42
            sw      t5,8(t4)
            vsetvli zero,a4,e8,m8,ta,ma  <<--- a4 as avl
    
    Actually, this vsetvl is redundant.
    The root cause we include full available optimization in LCM local data computation.
    
    full available optimization should be after LCM computation.
    
            PR target/112929
            PR target/112988
    
    gcc/ChangeLog:
    
            * config/riscv/riscv-vsetvl.cc
            (pre_vsetvl::compute_lcm_local_properties): Remove full available.
            (pre_vsetvl::pre_global_vsetvl_info): Add full available optimization.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.target/riscv/rvv/vsetvl/pr112929.c: New test.
            * gcc.target/riscv/rvv/vsetvl/pr112988.c: New test.

Diff:
---
 gcc/config/riscv/riscv-vsetvl.cc                   | 14 ++++-
 .../gcc.target/riscv/rvv/vsetvl/pr112929.c         | 58 ++++++++++++++++++
 .../gcc.target/riscv/rvv/vsetvl/pr112988.c         | 69 ++++++++++++++++++++++
 3 files changed, 139 insertions(+), 2 deletions(-)

diff --git a/gcc/config/riscv/riscv-vsetvl.cc b/gcc/config/riscv/riscv-vsetvl.cc
index ed5a2b58ab0..6af8d8429ab 100644
--- a/gcc/config/riscv/riscv-vsetvl.cc
+++ b/gcc/config/riscv/riscv-vsetvl.cc
@@ -2723,8 +2723,7 @@ pre_vsetvl::compute_lcm_local_properties ()
       vsetvl_info &header_info = block_info.get_entry_info ();
       vsetvl_info &footer_info = block_info.get_exit_info ();
 
-      if (header_info.valid_p ()
-	  && (anticipated_exp_p (header_info) || block_info.full_available))
+      if (header_info.valid_p () && anticipated_exp_p (header_info))
 	bitmap_set_bit (m_antloc[bb_index],
 			get_expr_index (m_exprs, header_info));
 
@@ -3224,6 +3223,17 @@ pre_vsetvl::pre_global_vsetvl_info ()
       info.set_delete ();
     }
 
+  /* Remove vsetvl infos if all precessors are available to the block.  */
+  for (const bb_info *bb : crtl->ssa->bbs ())
+    {
+      vsetvl_block_info &block_info = get_block_info (bb);
+      if (block_info.empty_p () || !block_info.full_available)
+	continue;
+
+      vsetvl_info &info = block_info.get_entry_info ();
+      info.set_delete ();
+    }
+
   for (const bb_info *bb : crtl->ssa->bbs ())
     {
       vsetvl_block_info &block_info = get_block_info (bb);
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr112929.c b/gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr112929.c
new file mode 100644
index 00000000000..0435e5dbc56
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr112929.c
@@ -0,0 +1,58 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gcv -mabi=lp64d -O3" } */
+
+int printf(char *, ...);
+int a, l, i, p, q, t, n, o;
+int *volatile c;
+static int j;
+static struct pack_1_struct d;
+long e;
+char m = 5;
+short s;
+
+#pragma pack(1)
+struct pack_1_struct {
+  long c;
+  int d;
+  int e;
+  int f;
+  int g;
+  int h;
+  int i;
+} h, r = {1}, *f = &h, *volatile g;
+
+void add_em_up(int count, ...) {
+  __builtin_va_list ap;
+  __builtin_va_start(ap, count);
+  __builtin_va_end(ap);
+}
+
+int main() {
+  int u;
+  j = 0;
+
+  for (; j < 9; ++j) {
+    u = ++t ? a : 0;
+    if (u) {
+      int *v = &d.d;
+      *v = g || e;
+      *c = 0;
+      *f = h;
+    }
+    s = l && c;
+    o = i;
+    d.f || (p = 0);
+    q |= n;
+  }
+
+  r = *f;
+
+  add_em_up(1, 1);
+
+  printf("%d\n", m);
+}
+
+/* { dg-final { scan-assembler-times {vsetvli} 2 { target { no-opts "-O0"  no-opts "-Os" no-opts "-Oz" no-opts "-funroll-loops" no-opts "-g" } } } } */
+/* { dg-final { scan-assembler-not {vsetivli} } } */
+/* { dg-final { scan-assembler-times {vsetvli\tzero,\s*[a-x0-9]+,\s*e8,\s*m8,\s*t[au],\s*m[au]} 2 { target { no-opts "-O0"  no-opts "-Os" no-opts "-Oz" no-opts "-funroll-loops" no-opts "-g" } } } } */
+/* { dg-final { scan-assembler-times {li\t[a-x0-9]+,\s*32} 2 { target { no-opts "-O0"  no-opts "-Os" no-opts "-Oz" no-opts "-funroll-loops" no-opts "-g" } } } } */
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr112988.c b/gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr112988.c
new file mode 100644
index 00000000000..6f983ef8bb5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr112988.c
@@ -0,0 +1,69 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gcv -mabi=lp64d -O3" } */
+
+int a = 0;
+int p, q, r, x = 230;
+short d;
+int e[256];
+static struct f w;
+int *c = &r;
+
+short y(short z) {
+  return z * d;
+}
+
+#pragma pack(1)
+struct f {
+  int g;
+  short h;
+  int j;
+  char k;
+  char l;
+  long m;
+  long n;
+  int o;
+} s = {1}, v, t, *u = &v, *b = &s;
+
+void add_em_up(int count, ...) {
+  __builtin_va_list ap;
+  __builtin_va_start(ap, count);
+  __builtin_va_end(ap);
+}
+
+int main() {
+  int i = 0;
+  for (; i < 256; i++)
+    e[i] = i;
+
+  p = 0;
+  for (; p <= 0; p++) {
+    *c = 4;
+    *u = t;
+    x |= y(6 >= q);
+  }
+
+  *b = w;
+
+  add_em_up(1, 1);
+
+  if (a != 0)
+    return 1;
+  if (q != 0)
+    return 2;
+  if (p != 1)
+    return 3;
+  if (r != 4)
+    return 4;
+  if (x != 0xE6)
+    return 5;
+  if (d != 0)
+    return 6;
+
+  return 0;
+}
+
+/* { dg-final { scan-assembler-times {vsetvli} 1 } } */
+/* { dg-final { scan-assembler-times {vsetivli} 1 } } */
+/* { dg-final { scan-assembler-times {vsetivli\tzero,\s*4,\s*e32,\s*m1,\s*t[au],\s*m[au]} 1 } } */
+/* { dg-final { scan-assembler-times {vsetvli\tzero,\s*[a-x0-9]+,\s*e8,\s*m8,\s*t[au],\s*m[au]} 1 } } */
+/* { dg-final { scan-assembler-times {li\t[a-x0-9]+,\s*32} 1 } } */