From e1133c0205a7e2a65834a1af780b8da15eead2a9 Mon Sep 17 00:00:00 2001
From: Marek Polacek <polacek@redhat.com>
Date: Mon, 7 Mar 2022 16:15:46 -0500
Subject: [PATCH] rtl: ICE with thread_local and inline asm [PR104777]
In r270550, Jakub fixed classify_insn to handle asm goto: if the asm can
jump to a label, the insn should be a JUMP_INSN.
However, as the following testcase shows, non-null ASM_OPERANDS_LABEL_VEC
doesn't guarantee that the rtx has any actual labels it can branch to.
Here, the rtvec has 0 elements because expand_asm_stmt created it:
rtvec labelvec = rtvec_alloc (nlabels); // nlabels == 0
This causes an ICE in update_br_prob_note: BRANCH_EDGE (bb) crashes
because there's no branch edge. I think we can fix this by checking
that there is at least one label the asm can jump to before wrapping
the ASM_OPERANDS in a JUMP_INSN.
PR rtl-optimization/104777
gcc/ChangeLog:
* rtl.cc (classify_insn): For ASM_OPERANDS, return JUMP_INSN only if
ASM_OPERANDS_LABEL_VEC has at least one element.
gcc/testsuite/ChangeLog:
* gcc.dg/torture/tls/pr104777.c: New test.
---
gcc/rtl.cc | 4 +--
gcc/testsuite/gcc.dg/torture/tls/pr104777.c | 30 +++++++++++++++++++++
2 files changed, 32 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/torture/tls/pr104777.c
diff --git a/gcc/rtl.cc b/gcc/rtl.cc
index f17474bfee19..86c322b19ca1 100644
--- a/gcc/rtl.cc
+++ b/gcc/rtl.cc
@@ -765,7 +765,7 @@ classify_insn (rtx x)
return CALL_INSN;
if (ANY_RETURN_P (x))
return JUMP_INSN;
- if (GET_CODE (x) == ASM_OPERANDS && ASM_OPERANDS_LABEL_VEC (x))
+ if (GET_CODE (x) == ASM_OPERANDS && ASM_OPERANDS_LABEL_LENGTH (x))
return JUMP_INSN;
if (GET_CODE (x) == SET)
{
@@ -794,7 +794,7 @@ classify_insn (rtx x)
if (has_return_p)
return JUMP_INSN;
if (GET_CODE (XVECEXP (x, 0, 0)) == ASM_OPERANDS
- && ASM_OPERANDS_LABEL_VEC (XVECEXP (x, 0, 0)))
+ && ASM_OPERANDS_LABEL_LENGTH (XVECEXP (x, 0, 0)))
return JUMP_INSN;
}
#ifdef GENERATOR_FILE
diff --git a/gcc/testsuite/gcc.dg/torture/tls/pr104777.c b/gcc/testsuite/gcc.dg/torture/tls/pr104777.c
new file mode 100644
index 000000000000..abaf59731fcc
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/tls/pr104777.c
@@ -0,0 +1,30 @@
+/* PR rtl-optimization/104777 */
+/* { dg-do compile } */
+/* { dg-require-effective-target tls } */
+
+int savestate_r;
+int savestate_ssb;
+extern void abort();
+__thread int loop;
+void f (void)
+{
+ int savestate_r0_5;
+ int savestate_r1_6;
+
+ __asm__("" : "=m" (savestate_ssb), "=r" (savestate_r));
+ savestate_r0_5 = savestate_r;
+ if (savestate_r0_5 == 0)
+ {
+ __asm__ __volatile__("" : : "m" (loop));
+ abort ();
+ }
+
+ __asm__("" : "=m" (savestate_ssb), "=r" (savestate_r));
+ savestate_r1_6 = savestate_r;
+ if (savestate_r1_6 != 0)
+ return;
+
+ __asm__ __volatile__("" : : "m" (loop));
+ abort ();
+
+}
--
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