[PATCH] Fix handling of very long asm statements in inliner

[Andi Kleen]

An auto generated program with a 6.4mio line asm statement gave
with 4.7 and 4.8:

xxx.c:6400017:1: internal compiler error: in account_size_time, at
ipa-inline-analysis.c:601

The problem is that the inliner counts the number of lines in the asm
statement and multiplies that with a weight. With the weight this
overflows 32bit signed int, and triggers an assert for negative time.

Fix this by limiting the number of lines to 1000 for asm cost
estimation. The RTL backend also does similar multiplications for
jump shortening. I haven't tried to address this, but presumably
it's less likely to result in a failure.

Passes test suite on x86_64-linux.

Ok for 4.7 and 4.8?

2013-02-17  Andi Kleen  <ak@linux.intel.com>

	* tree-inline.c (estimate_num_insns): Limit asm cost to 1000.

diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c
index 2a1b692..7f8f2f2 100644
--- a/gcc/tree-inline.c
+++ b/gcc/tree-inline.c
@@ -3595,7 +3595,14 @@ estimate_num_insns (gimple stmt, eni_weights *weights)
       return 0;
 
     case GIMPLE_ASM:
-      return asm_str_count (gimple_asm_string (stmt));
+      {
+	int count = asm_str_count (gimple_asm_string (stmt));
+	/* 1000 means infinity. This avoids overflows later
+	   with very long asm statements.  */
+	if (count > 1000)
+	  count = 1000;
+	return count;
+      }
 
     case GIMPLE_RESX:
       /* This is either going to be an external function call with one
-- 
ak@linux.intel.com -- Speaking for myself only.