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[PARCH 2/2, x86, PR63534] Fix darwin bootstrap


Hi,

Some instructions (like one in PR63534) could have hidden use of PIC register.
Therefore we need to leave SET_GOT not deleted till reload completed.
The patch prevents SET_GOT from deleting while PIC register is pseudo.

Is it ok?

ChangeLog:

2014-10-17  Evgeny Stupachenko  <evstupac@gmail.com>

        PR target/63534
        * cse.c (delete_trivially_dead_insns): Consider PIC register is used
        while it is pseudo.
        * dse.c (deletable_insn_p): Likewise.

diff --git a/gcc/cse.c b/gcc/cse.c
index be2f31b..062ba45 100644
--- a/gcc/cse.c
+++ b/gcc/cse.c
@@ -6953,6 +6953,11 @@ delete_trivially_dead_insns (rtx_insn *insns, int nreg)
       /* If no debug insns can be present, COUNTS is just an array
         which counts how many times each pseudo is used.  */
     }
+  /* Pseudo PIC register should be considered as used due to possible
+     new usages generated.  */
+  if (pic_offset_table_rtx
+      && REGNO (pic_offset_table_rtx) >= FIRST_PSEUDO_REGISTER)
+    counts[REGNO (pic_offset_table_rtx)]++;
   /* Go from the last insn to the first and delete insns that only set unused
      registers or copy a register to itself.  As we delete an insn, remove
      usage counts for registers it uses.
diff --git a/gcc/dce.c b/gcc/dce.c
index 5b7d36e..a52a59c 100644
--- a/gcc/dce.c
+++ b/gcc/dce.c
@@ -127,6 +127,10 @@ deletable_insn_p (rtx_insn *insn, bool fast,
bitmap arg_stores)
     if (HARD_REGISTER_NUM_P (DF_REF_REGNO (def))
        && global_regs[DF_REF_REGNO (def)])
       return false;
+    /* Initialization of pseudo PIC register should never be removed.  */
+    else if (DF_REF_REG (def) == pic_offset_table_rtx
+            && REGNO (pic_offset_table_rtx) >= FIRST_PSEUDO_REGISTER)
+      return false;

   body = PATTERN (insn);
   switch (GET_CODE (body))


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