[PATCH] Fix ICE with invalid use of flags output operand

[Bernd Edlinger]

Hi,

this fixes an ICE that happens when an asm statement tries to print
the flags output operand.

Boot-strapped and reg-tested on x86_64-linux-gnu.
OK for trunk?


Thanks
Bernd.
gcc:
2016-06-11  Bernd Edlinger  <bernd.edlin...@hotmail.de>

        * config/i386/i386.c (print_reg): Emit an error message on attempt to
        print FLAGS_REG.

testsuite:
2016-06-11  Bernd Edlinger  <bernd.edlin...@hotmail.de>

        * gcc.target/i386/asm-flag-7.c: New test.

Index: gcc/config/i386/i386.c
===================================================================
--- gcc/config/i386/i386.c	(revision 237323)
+++ gcc/config/i386/i386.c	(working copy)
@@ -17180,10 +17180,15 @@ print_reg (rtx x, int code, FILE *file)
 
   gcc_assert (regno != ARG_POINTER_REGNUM
 	      && regno != FRAME_POINTER_REGNUM
-	      && regno != FLAGS_REG
 	      && regno != FPSR_REG
 	      && regno != FPCR_REG);
 
+  if (regno == FLAGS_REG)
+    {
+      output_operand_lossage ("invalid use of asm flag output");
+      return;
+    }
+
   duplicated = code == 'd' && TARGET_AVX;
 
   switch (msize)
Index: gcc/testsuite/gcc.target/i386/asm-flag-7.c
===================================================================
--- gcc/testsuite/gcc.target/i386/asm-flag-7.c	(revision 0)
+++ gcc/testsuite/gcc.target/i386/asm-flag-7.c	(working copy)
@@ -0,0 +1,9 @@
+/* Test error conditions of asm flag outputs.  */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+void test(void)
+{
+  char x;
+  asm("# %0" : "=@ccz"(x)); /* { dg-error "invalid use of asm flag output" } */
+}