On 22-04-14 17:05, Tom de Vries wrote:
I've updated the fuse-caller-save patch series to model non-callee call clobbers
in CALL_INSN_FUNCTION_USAGE.
Eric,
Richard Sandiford mentioned here (
http://gcc.gnu.org/ml/gcc-patches/2014-04/msg00870.html ):
...
Although we really should have a utility function like use_reg, but for
clobbers, so that the above would become:
clobber_reg (&CALL_INSN_FUNCTION_USAGE (insn), gen_rtx_REG (word_mode, 18));
...
I've implemented a patch that adds clobber_reg and clobber_reg_mode, similar to
use_reg and use_reg_mode.
Bootstrapped and reg-tested on x86_64 as part of the fuse-caller-save series.
OK for trunk?
Thanks,
- Tom
2014-04-18 Tom de Vries
* expr.c (clobber_reg_mode): New function.
* expr.h (clobber_reg): New function.
diff --git a/gcc/expr.c b/gcc/expr.c
index 72e4401..fc58eb7f 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -2396,6 +2396,18 @@ use_reg_mode (rtx *call_fusage, rtx reg, enum machine_mode mode)
= gen_rtx_EXPR_LIST (mode, gen_rtx_USE (VOIDmode, reg), *call_fusage);
}
+/* Add a CLOBBER expression for REG to the (possibly empty) list pointed
+ to by CALL_FUSAGE. REG must denote a hard register. */
+
+void
+clobber_reg_mode (rtx *call_fusage, rtx reg, enum machine_mode mode)
+{
+ gcc_assert (REG_P (reg) && REGNO (reg) < FIRST_PSEUDO_REGISTER);
+
+ *call_fusage
+= gen_rtx_EXPR_LIST (mode, gen_rtx_CLOBBER (VOIDmode, reg), *call_fusage);
+}
+
/* Add USE expressions to *CALL_FUSAGE for each of NREGS consecutive regs,
starting at REGNO. All of these registers must be hard registers. */
diff --git a/gcc/expr.h b/gcc/expr.h
index 524da67..1823feb 100644
--- a/gcc/expr.h
+++ b/gcc/expr.h
@@ -346,6 +346,7 @@ extern void copy_blkmode_from_reg (rtx, rtx, tree);
/* Mark REG as holding a parameter for the next CALL_INSN.
Mode is TYPE_MODE of the non-promoted parameter, or VOIDmode. */
extern void use_reg_mode (rtx *, rtx, enum machine_mode);
+extern void clobber_reg_mode (rtx *, rtx, enum machine_mode);
extern rtx copy_blkmode_to_reg (enum machine_mode, tree);
@@ -356,6 +357,13 @@ use_reg (rtx *fusage, rtx reg)
use_reg_mode (fusage, reg, VOIDmode);
}
+/* Mark REG as clobbered by the call with FUSAGE as CALL_INSN_FUNCTION_USAGE. */
+static inline void
+clobber_reg (rtx *fusage, rtx reg)
+{
+ clobber_reg_mode (fusage, reg, VOIDmode);
+}
+
/* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
for the next CALL_INSN. */
extern void use_regs (rtx *, int, int);