From: Jakub Jelinek <jakub@redhat.com>
Date: Thu, 9 Feb 2012 21:36:54 +0000 (+0100)
Subject: backport: re PR rtl-optimization/51767 (ICE with degenerated asm goto)
X-Git-Tag: releases/gcc-4.5.4~229
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=15e45b414da575096214b01fbf30f0011f88397a;p=thirdparty%2Fgcc.git

backport: re PR rtl-optimization/51767 (ICE with degenerated asm goto)

	Backported from mainline
	2012-01-05  Jakub Jelinek  <jakub@redhat.com>

	PR rtl-optimization/51767
	* cfgrtl.c (force_nonfallthru_and_redirect): Force addition
	of jump_block and add an extra edge for degenerated asm gotos.

	* gcc.c-torture/compile/pr51767.c: New test.

From-SVN: r184072
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b71e79facaf3..fe4c69ef8ae9 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -3,6 +3,10 @@
 	Backported from mainline
 	2012-01-05  Jakub Jelinek  <jakub@redhat.com>
 
+	PR rtl-optimization/51767
+	* cfgrtl.c (force_nonfallthru_and_redirect): Force addition
+	of jump_block and add an extra edge for degenerated asm gotos.
+
 	PR middle-end/51768
 	* stmt.c (check_unique_operand_names): Don't ICE during error
 	reporting if i is from labels chain.
diff --git a/gcc/cfgrtl.c b/gcc/cfgrtl.c
index db2c56e7ae61..814ad7846f42 100644
--- a/gcc/cfgrtl.c
+++ b/gcc/cfgrtl.c
@@ -1116,6 +1116,7 @@ force_nonfallthru_and_redirect (edge e, basic_block target)
   rtx note;
   edge new_edge;
   int abnormal_edge_flags = 0;
+  bool asm_goto_edge = false;
   int loc;
 
   /* In the case the last instruction is conditional jump to the next
@@ -1195,8 +1196,28 @@ force_nonfallthru_and_redirect (edge e, basic_block target)
 	}
     }
 
-  if (EDGE_COUNT (e->src->succs) >= 2 || abnormal_edge_flags)
+  /* If e->src ends with asm goto, see if any of the ASM_OPERANDS_LABELs
+     don't point to target label.  */
+  if (JUMP_P (BB_END (e->src))
+      && target != EXIT_BLOCK_PTR
+      && e->dest == target
+      && (e->flags & EDGE_FALLTHRU)
+      && (note = extract_asm_operands (PATTERN (BB_END (e->src)))))
     {
+      int i, n = ASM_OPERANDS_LABEL_LENGTH (note);
+
+      for (i = 0; i < n; ++i)
+	if (XEXP (ASM_OPERANDS_LABEL (note, i), 0) == BB_HEAD (target))
+	  {
+	    asm_goto_edge = true;
+	    break;
+	  }
+    }
+
+  if (EDGE_COUNT (e->src->succs) >= 2 || abnormal_edge_flags || asm_goto_edge)
+    {
+      gcov_type count = e->count;
+      int probability = e->probability;
       /* Create the new structures.  */
 
       /* If the old block ended with a tablejump, skip its table
@@ -1207,7 +1228,7 @@ force_nonfallthru_and_redirect (edge e, basic_block target)
       note = NEXT_INSN (note);
 
       jump_block = create_basic_block (note, NULL, e->src);
-      jump_block->count = e->count;
+      jump_block->count = count;
       jump_block->frequency = EDGE_FREQUENCY (e);
       jump_block->loop_depth = target->loop_depth;
 
@@ -1223,13 +1244,27 @@ force_nonfallthru_and_redirect (edge e, basic_block target)
 
       /* Wire edge in.  */
       new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU);
-      new_edge->probability = e->probability;
-      new_edge->count = e->count;
+      new_edge->probability = probability;
+      new_edge->count = count;
 
       /* Redirect old edge.  */
       redirect_edge_pred (e, jump_block);
       e->probability = REG_BR_PROB_BASE;
 
+      /* If asm goto has any label refs to target's label,
+	 add also edge from asm goto bb to target.  */
+      if (asm_goto_edge)
+	{
+	  new_edge->probability /= 2;
+	  new_edge->count /= 2;
+	  jump_block->count /= 2;
+	  jump_block->frequency /= 2;
+	  new_edge = make_edge (new_edge->src, target,
+				e->flags & ~EDGE_FALLTHRU);
+	  new_edge->probability = probability - probability / 2;
+	  new_edge->count = count - count / 2;
+	}
+
       new_bb = jump_block;
     }
   else
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 9f0b74bd6883..1c950d84b858 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -3,6 +3,9 @@
 	Backported from mainline
 	2012-01-05  Jakub Jelinek  <jakub@redhat.com>
 
+	PR rtl-optimization/51767
+	* gcc.c-torture/compile/pr51767.c: New test.
+
 	PR middle-end/51768
 	* c-c++-common/pr51768.c: New test.
 
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr51767.c b/gcc/testsuite/gcc.c-torture/compile/pr51767.c
new file mode 100644
index 000000000000..62a192d660d8
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr51767.c
@@ -0,0 +1,23 @@
+/* PR rtl-optimization/51767 */
+
+extern void fn1 (void), fn2 (void);
+
+static inline __attribute__((always_inline)) int
+foo (int *x, long y)
+{
+  asm goto ("" : : "r" (x), "r" (y) : "memory" : lab);
+  return 0;
+lab:
+  return 1;
+}
+
+void
+bar (int *x)
+{
+  if (foo (x, 23))
+    fn1 ();
+  else
+    fn2 ();
+
+  foo (x, 2);
+}