[PATCH] Fix power8 non-delegitimized UNSPEC UNSPEC_FUSION_GPR messages

[Jakub Jelinek]

Hi!

My recent changes to UNSPEC handling in dwarf2out.c apparently broke
(non-release checking) regtest on powerpc*, a lot of
note: non-delegitimized UNSPEC UNSPEC_FUSION_GPR (73) found in variable location
messages are emitted while compiling pretty much anything with -mcpu=power8
or later.

The problem is that debug insns say some variable lives in the result of
UNSPEC_FUSION_GPR and var-tracking manages to optimize the operand of that
UNSPEC from a complex MEM into a LABEL_REF.  For UNSPECs that don't have any
constant arguments dwarf2out is silent as before, but for those that have
CONSTANT_P operands it hints that it would be nice to delegitimize those.

Apparently UNSPEC_FUSION_GPR wraps a MEM that isn't valid in a normal insn,
as it includes both the high and lo_sum parts, but otherwise it is something
that is completely ok for debug info purposes.
So, this patch delegitimizes this UNSPEC to its argument.

Bootstrapped/regtested on powerpc64le-linux, ok for trunk?

2019-01-08  Jakub Jelinek  <jakub@redhat.com>

	* config/rs6000/rs6000.c (rs6000_delegitimize_address): Delegitimize
	UNSPEC_FUSION_GPR to its argument.  Formatting fixes.

--- gcc/config/rs6000/rs6000.c.jj	2019-01-01 12:37:44.885520010 +0100
+++ gcc/config/rs6000/rs6000.c	2019-01-08 13:22:48.846995153 +0100
@@ -8388,14 +8388,17 @@ rs6000_delegitimize_address (rtx orig_x)
 {
   rtx x, y, offset;
 
+  if (GET_CODE (orig_x) == UNSPEC && XINT (orig_x, 1) == UNSPEC_FUSION_GPR)
+    orig_x = XVECEXP (orig_x, 0, 0);
+
   orig_x = delegitimize_mem_from_attrs (orig_x);
+
   x = orig_x;
   if (MEM_P (x))
     x = XEXP (x, 0);
 
   y = x;
-  if (TARGET_CMODEL != CMODEL_SMALL
-      && GET_CODE (y) == LO_SUM)
+  if (TARGET_CMODEL != CMODEL_SMALL && GET_CODE (y) == LO_SUM)
     y = XEXP (y, 1);
 
   offset = NULL_RTX;
@@ -8407,8 +8410,7 @@ rs6000_delegitimize_address (rtx orig_x)
       y = XEXP (y, 0);
     }
 
-  if (GET_CODE (y) == UNSPEC
-      && XINT (y, 1) == UNSPEC_TOCREL)
+  if (GET_CODE (y) == UNSPEC && XINT (y, 1) == UNSPEC_TOCREL)
     {
       y = XVECEXP (y, 0, 0);
 
@@ -8435,8 +8437,7 @@ rs6000_delegitimize_address (rtx orig_x)
       && GET_CODE (XEXP (orig_x, 1)) == CONST)
     {
       y = XEXP (XEXP (orig_x, 1), 0);
-      if (GET_CODE (y) == UNSPEC
-	  && XINT (y, 1) == UNSPEC_MACHOPIC_OFFSET)
+      if (GET_CODE (y) == UNSPEC && XINT (y, 1) == UNSPEC_MACHOPIC_OFFSET)
 	return XVECEXP (y, 0, 0);
     }
 


	Jakub