From 330bb06485b18bae3effe83b45b97dbdcd543367 Mon Sep 17 00:00:00 2001
From: Juzhe-Zhong <juzhe.zhong@rivai.ai>
Date: Mon, 11 Dec 2023 14:43:34 +0800
Subject: [PATCH] RISC-V: Fix ICE in extract_single_source
This patch fixes the following ICE in VSETVL PASS:
bug.c:39:1: internal compiler error: Segmentation fault
39 | }
| ^
0x1ad5a08 crash_signal
../../../../gcc/gcc/toplev.cc:316
0x7f7f55feb90f ???
./signal/../sysdeps/unix/sysv/linux/x86_64/libc_sigaction.c:0
0x218d7c7 extract_single_source
../../../../gcc/gcc/config/riscv/riscv-vsetvl.cc:583
0x218d95d extract_single_source
../../../../gcc/gcc/config/riscv/riscv-vsetvl.cc:604
0x218fbc5 pre_vsetvl::compute_lcm_local_properties()
../../../../gcc/gcc/config/riscv/riscv-vsetvl.cc:2703
0x2190ef4 pre_vsetvl::earliest_fuse_vsetvl_info()
../../../../gcc/gcc/config/riscv/riscv-vsetvl.cc:2890
0x2193e62 pass_vsetvl::lazy_vsetvl()
../../../../gcc/gcc/config/riscv/riscv-vsetvl.cc:3537
0x219406a pass_vsetvl::execute(function*)
../../../../gcc/gcc/config/riscv/riscv-vsetvl.cc:3584
The rootcause we have a case that the def info can not be traced:
(insn 208 327 333 27 (use (reg/i:DI 10 a0)) "bug.c":36:1 -1
(nil))
It's obvious, we conservatively disable any optimization in this situation if
AVL def_info can not be tracded.
Committed as it is obvious.
gcc/ChangeLog:
* config/riscv/riscv-vsetvl.cc (extract_single_source): Fix ICE.
gcc/testsuite/ChangeLog:
* gcc.target/riscv/rvv/vsetvl/avl_use_bug-1.c: New test.
---
gcc/config/riscv/riscv-vsetvl.cc | 2 +
.../riscv/rvv/vsetvl/avl_use_bug-1.c | 39 +++++++++++++++++++
2 files changed, 41 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/vsetvl/avl_use_bug-1.c
diff --git a/gcc/config/riscv/riscv-vsetvl.cc b/gcc/config/riscv/riscv-vsetvl.cc
index 90477f331d7c..ed5a2b58ab04 100644
--- a/gcc/config/riscv/riscv-vsetvl.cc
+++ b/gcc/config/riscv/riscv-vsetvl.cc
@@ -579,6 +579,8 @@ extract_single_source (set_info *set)
if (!set->insn ()->is_phi ())
return nullptr;
hash_set<set_info *> sets = get_all_sets (set, true, false, true);
+ if (sets.is_empty ())
+ return nullptr;
insn_info *first_insn = (*sets.begin ())->insn ();
if (first_insn->is_artificial ())
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/vsetvl/avl_use_bug-1.c b/gcc/testsuite/gcc.target/riscv/rvv/vsetvl/avl_use_bug-1.c
new file mode 100644
index 000000000000..330221c2d7b4
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/vsetvl/avl_use_bug-1.c
@@ -0,0 +1,39 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gcv_zvl256b -mabi=lp64 --param=riscv-autovec-lmul=m8 --param=riscv-autovec-preference=fixed-vlmax -O2" } */
+
+struct a_struct
+{
+ unsigned char a_character;
+};
+
+struct a_struct an_array[5];
+struct a_struct *a_ptr;
+int yabba = 1;
+
+int
+f (a, b)
+ unsigned char a;
+ unsigned long b;
+{
+ long i, j, p, q, r, s;
+
+ if (b != (unsigned long) 0)
+ {
+ if (yabba)
+ return -1;
+ s = 4000000 / b;
+ for (i = 0; i < 11; i++)
+ {
+ for (j = 0; j < 256; j++)
+ {
+ if (((p - s < 0) ? -s : 0) < (( q - s < 0) ? -s : q))
+ r = i;
+ }
+ }
+ }
+
+ if (yabba)
+ return 0;
+ a_ptr = &an_array[a];
+ a_ptr->a_character = (unsigned char) r;
+}
--
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