Re: [PING][PATCH] Move the check for any_condjump_p from sched-deps to target macros

[Jeff Law]

On 04/26/2017 06:50 AM, Hurugalawadi, Naveen wrote:
Hi Wilco,
Thanks for reviewing the patch.

The return false seems incorrect - it means a core can either have
FUSE_CMP_BRANCH or FUSE_ALU_BRANCH but not both.
Thanks for pointing out about the confusion.
Modified the code as required.

Bootstrapped and Regression tested on AArch64 and X86_64.
Please review the patch and let us know if its okay?

Thanks,
Naveen


fusion-anycond-jump-1.patch


diff --git a/gcc/sched-deps.c b/gcc/sched-deps.c
index b2393bf..b15a865 100644
--- a/gcc/sched-deps.c
+++ b/gcc/sched-deps.c
@@ -2835,33 +2835,16 @@ sched_macro_fuse_insns (rtx_insn *insn)
  {
    rtx_insn *prev;
  
-  if (any_condjump_p (insn))
-    {
-      unsigned int condreg1, condreg2;
-      rtx cc_reg_1;
-      targetm.fixed_condition_code_regs (&condreg1, &condreg2);
-      cc_reg_1 = gen_rtx_REG (CCmode, condreg1);
-      prev = prev_nonnote_nondebug_insn (insn);
-      if (!reg_referenced_p (cc_reg_1, PATTERN (insn))
-          || !prev
-          || !modified_in_p (cc_reg_1, prev))
-        return;
-    }
-  else
-    {
-      rtx insn_set = single_set (insn);
-
-      prev = prev_nonnote_nondebug_insn (insn);
-      if (!prev
-          || !insn_set
-          || !single_set (prev))
-        return;
+  rtx insn_set = single_set (insn);
  
-    }
+  prev = prev_nonnote_nondebug_insn (insn);
+  if (!prev
+      || !insn_set
+      || !single_set (prev))
+    return;
  
    if (targetm.sched.macro_fusion_pair_p (prev, insn))
      SCHED_GROUP_P (insn) = 1;
-
  }
Doesn't this avoid calling the target hook in cases where it used to 
call it before?

Consider a conditional jump inside a parallel that is not a single set.

Previously that could call the target hook and potentially set 
SCHED_GROUP_P.  But after your change I think it would return without 
ever querying the backend.

jeff