From 17a938e841d439c5ea73b4fcbd7091ae448a9257 Mon Sep 17 00:00:00 2001
From: Segher Boessenkool <segher@kernel.crashing.org>
Date: Wed, 30 Nov 2016 15:47:01 +0100
Subject: [PATCH] ira: Don't substitute into TRAP_IF insns (PR78610)
In the testcase, IRA propagates a constant into a TRAP_IF insn, which
then becomes an unconditional trap. Unconditional traps are control
flow insns so doing this requires surgery on the cfg. We cannot do
that here, so instead refuse to do the substitution.
PR rtl-optimization/78610
* ira.c (combine_and_move_insns): Don't substitute into TRAP_IF
instructions.
gcc/testsuite/
PR rtl-optimization/78610
* gcc.c-torture/compile/pr78610.c: New testcase.
From-SVN: r243028
---
gcc/ChangeLog | 6 ++++++
gcc/ira.c | 5 +++++
gcc/testsuite/ChangeLog | 5 +++++
gcc/testsuite/gcc.c-torture/compile/pr78610.c | 14 ++++++++++++++
4 files changed, 30 insertions(+)
create mode 100644 gcc/testsuite/gcc.c-torture/compile/pr78610.c
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 0fc87d259a86..97daa79d06b8 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2016-11-30 Segher Boessenkool <segher@kernel.crashing.org>
+
+ PR rtl-optimization/78610
+ * ira.c (combine_and_move_insns): Don't substitute into TRAP_IF
+ instructions.
+
2016-11-30 Bin Cheng <bin.cheng@arm.com>
PR tree-optimization/78574
diff --git a/gcc/ira.c b/gcc/ira.c
index 358110b6a318..ab322889c6c5 100644
--- a/gcc/ira.c
+++ b/gcc/ira.c
@@ -3669,6 +3669,11 @@ combine_and_move_insns (void)
if (JUMP_P (use_insn))
continue;
+ /* Also don't substitute into a conditional trap insn -- it can become
+ an unconditional trap, and that is a flow control insn. */
+ if (GET_CODE (PATTERN (use_insn)) == TRAP_IF)
+ continue;
+
df_ref def = DF_REG_DEF_CHAIN (regno);
gcc_assert (DF_REG_DEF_COUNT (regno) == 1 && DF_REF_INSN_INFO (def));
rtx_insn *def_insn = DF_REF_INSN (def);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index eac361b5f857..7164611f9fff 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-11-30 Segher Boessenkool <segher@kernel.crashing.org>
+
+ PR rtl-optimization/78610
+ * gcc.c-torture/compile/pr78610.c: New testcase.
+
2016-11-30 Bin Cheng <bin.cheng@arm.com>
PR tree-optimization/78574
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr78610.c b/gcc/testsuite/gcc.c-torture/compile/pr78610.c
new file mode 100644
index 000000000000..0415ae6d9dff
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr78610.c
@@ -0,0 +1,14 @@
+/* PR rtl-optimization/78610 */
+
+unsigned int ao, gl;
+
+void
+ri (void)
+{
+ for (;;)
+ {
+ if (ao != 1)
+ ao /= 0;
+ gl = 0;
+ }
+}
--
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