[PATCH, ARM] ICE when building kernel raid6 neon code

[Zhenqiang Chen <zhenqiang.chen@linaro.org>]

Hi,

The patch fixes ICE when building kernel raid6 neon code.

lib/raid6/neon4.c: In function 'raid6_

neon4_gen_syndrome_real':
lib/raid6/neon4.c:113:1: internal compiler error: in
dwarf2out_frame_debug_adjust_cfa, at dwarf2cfi.c:1090
 }

https://bugs.launchpad.net/gcc-linaro/+bug/1268893

Root cause:
When expanding epilogue, REG_CFA_ADJUST_CFA NOTE is added to handle
dwarf info issue for shrink-wrap. But for TARGET_APCS_FRAME,
shrink-wrap is disabled. And not all dwarf info in
arm_expand_epilogue_apcs_frame are correctly updated.
arm_emit_vfp_multi_reg_pop is called by both
arm_expand_epilogue_apcs_frame and arm_expand_epilogue. So we should
not add the NOTE in arm_emit_vfp_multi_reg_pop if shrink-wrap is not
enabled.

Boot strap and no make check regression on ARM Chromebook.

OK for trunk?

Thanks!
-Zhenqiang

ChangeLog:
2014-01-15  Zhenqiang Chen  <zhenqiang.chen@linaro.org>

        * config/arm/arm.c (arm_emit_vfp_multi_reg_pop): Do not add
        REG_CFA_ADJUST_CFA NOTE if shrink-wrap is not enabled.

diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 18196b3..1ccb796 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -19890,8 +19890,12 @@ arm_emit_vfp_multi_reg_pop (int first_reg,
int num_regs, rtx base_reg)
   par = emit_insn (par);
   REG_NOTES (par) = dwarf;

-  arm_add_cfa_adjust_cfa_note (par, 2 * UNITS_PER_WORD * num_regs,
-                              base_reg, base_reg);
+  /* REG_CFA_ADJUST_CFA NOTE is added to handle dwarf info issue when
+     shrink-wrap is enabled.  So when shrink-wrap is not enabled, we should
+     not add the note.  */
+  if (flag_shrink_wrap)
+    arm_add_cfa_adjust_cfa_note (par, 2 * UNITS_PER_WORD * num_regs,
+                                base_reg, base_reg);
 }

 /* Generate and emit a pattern that will be recognized as LDRD
pattern.  If even