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[committed] Fix handling of global registers in MIPS prologues
- From: Richard Sandiford <rdsandiford at googlemail dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Sun, 17 Apr 2011 18:31:04 +0100
- Subject: [committed] Fix handling of global registers in MIPS prologues
PR 45074 showed up a rather embarrassing oversight in the MIPS backend:
global registers were still being treated as call-saved.
Fixed with the attached patch. Tested on mips64-linux-gnu and applied.
Richard
gcc/
* config/mips/mips.c (mips_cfun_call_saved_reg_p): Handle global
registers.
gcc/testsuite/
* gcc.target/mips/reg-var-1.c: New test.
Index: gcc/config/mips/mips.c
===================================================================
--- gcc/config/mips/mips.c 2011-04-16 09:02:10.000000000 +0100
+++ gcc/config/mips/mips.c 2011-04-17 11:14:53.000000000 +0100
@@ -9097,6 +9097,11 @@ mips_interrupt_extra_call_saved_reg_p (u
static bool
mips_cfun_call_saved_reg_p (unsigned int regno)
{
+ /* If the user makes an ordinarily-call-saved register global,
+ that register is no longer call-saved. */
+ if (global_regs[regno])
+ return false;
+
/* Interrupt handlers need to save extra registers. */
if (cfun->machine->interrupt_handler_p
&& mips_interrupt_extra_call_saved_reg_p (regno))
Index: gcc/testsuite/gcc.target/mips/reg-var-1.c
===================================================================
--- /dev/null 2011-04-17 10:56:28.045573347 +0100
+++ gcc/testsuite/gcc.target/mips/reg-var-1.c 2011-04-17 11:22:39.000000000 +0100
@@ -0,0 +1,16 @@
+/* { dg-do run } */
+register int g asm ("$18");
+
+void __attribute__((noinline))
+test (void)
+{
+ g = g + 1;
+}
+
+int
+main (void)
+{
+ g = 2;
+ test ();
+ return g != 3;
+}