1 files changed, 65 insertions, 0 deletions
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index bf831ea..db8fdcc 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -3430,6 +3430,71 @@ rs6000_hard_regno_nregs (int regno, enum machine_mode mode)
 
   return (GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
 }
+
+/* Change register usage conditional on target flags.  */
+void
+rs6000_conditional_register_usage (void)
+{
+  int i;
+
+  /* Set MQ register fixed (already call_used) if not POWER
+     architecture (RIOS1, RIOS2, RSC, and PPC601) so that it will not
+     be allocated.  */
+  if (! TARGET_POWER)
+    fixed_regs[64] = 1;
+
+  /* 64-bit AIX reserves GPR13 for thread-private data.  */
+  if (TARGET_64BIT)
+    fixed_regs[13] = call_used_regs[13]
+      = call_really_used_regs[13] = 1;
+
+  /* Conditionally disable FPRs.  */
+  if (TARGET_SOFT_FLOAT || !TARGET_FPRS)
+    for (i = 32; i < 64; i++)
+      fixed_regs[i] = call_used_regs[i]
+        = call_really_used_regs[i] = 1;
+
+  if (DEFAULT_ABI == ABI_V4
+      && PIC_OFFSET_TABLE_REGNUM != INVALID_REGNUM
+      && flag_pic == 2)
+    fixed_regs[RS6000_PIC_OFFSET_TABLE_REGNUM] = 1;
+
+  if (DEFAULT_ABI == ABI_V4
+      && PIC_OFFSET_TABLE_REGNUM != INVALID_REGNUM
+      && flag_pic == 1)
+    fixed_regs[RS6000_PIC_OFFSET_TABLE_REGNUM]
+      = call_used_regs[RS6000_PIC_OFFSET_TABLE_REGNUM]
+      = call_really_used_regs[RS6000_PIC_OFFSET_TABLE_REGNUM] = 1;
+
+  if (DEFAULT_ABI == ABI_DARWIN
+      && PIC_OFFSET_TABLE_REGNUM != INVALID_REGNUM)
+    global_regs[RS6000_PIC_OFFSET_TABLE_REGNUM]
+      = fixed_regs[RS6000_PIC_OFFSET_TABLE_REGNUM]
+      = call_used_regs[RS6000_PIC_OFFSET_TABLE_REGNUM]
+      = call_really_used_regs[RS6000_PIC_OFFSET_TABLE_REGNUM] = 1;
+
+  if (TARGET_ALTIVEC)
+    global_regs[VSCR_REGNO] = 1;
+
+  if (TARGET_SPE)
+    {
+      global_regs[SPEFSCR_REGNO] = 1;
+      fixed_regs[FIXED_SCRATCH]
+        = call_used_regs[FIXED_SCRATCH]
+	= call_really_used_regs[FIXED_SCRATCH] = 1;
+    }
+
+  if (! TARGET_ALTIVEC)
+    {
+      for (i = FIRST_ALTIVEC_REGNO; i <= LAST_ALTIVEC_REGNO; ++i)
+	fixed_regs[i] = call_used_regs[i] = call_really_used_regs[i] = 1;
+      call_really_used_regs[VRSAVE_REGNO] = 1;
+    }
+
+  if (TARGET_ALTIVEC_ABI)
+    for (i = FIRST_ALTIVEC_REGNO; i < FIRST_ALTIVEC_REGNO + 20; ++i)
+      call_used_regs[i] = call_really_used_regs[i] = 1;
+}
 
 /* Try to output insns to set TARGET equal to the constant C if it can
    be done in less than N insns.  Do all computations in MODE.