[26/32] Remove global call sets: regrename.c
diff mbox series

Message ID mptd0g6ve2m.fsf@arm.com
State New
Headers show
Series
  • Support multiple ABIs in the same translation unit
Related show

Commit Message

Richard Sandiford Sept. 11, 2019, 7:16 p.m. UTC
This patch makes regrename use a similar mask-and-clobber-set
pair to IRA when tracking whether registers are clobbered by
calls in a region.  Testing for a nonzero ABI mask is equivalent
to testing for a register that crosses a call.

Since AArch64 and c6x use regrename.h, they need to be updated
to include function-abi.h first.  AIUI this is preferred over
including function-abi.h in regrename.h.


2019-09-11  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* regrename.h (du_head::call_clobber_mask): New field.
	(du_head::need_caller_save_reg): Replace with...
	(du_head::call_abis): ...this new field.
	* regrename.c: Include function-abi.h.
	(call_clobbered_in_chain_p): New function.
	(check_new_reg_p): Use crtl->abi when deciding whether a register
	is free for use after RA.  Use call_clobbered_in_chain_p to test
	whether a candidate register would be clobbered by a call.
	(find_rename_reg): Don't add call-clobber conflicts here.
	(rename_chains): Check call_abis instead of need_caller_save_reg.
	(merge_chains): Update for changes to du_head.
	(build_def_use): Use call_insn_abi to get the ABI of the call insn
	target.  Record the ABI identifier in call_abis and the set of
	fully or partially clobbered registers in call_clobber_mask.
	Add fully-clobbered registers to hard_conflicts here rather
	than in find_rename_reg.
	* config/aarch64/cortex-a57-fma-steering.c: Include function-abi.h.
	(rename_single_chain): Check call_abis instead of need_caller_save_reg.
	* config/aarch64/falkor-tag-collision-avoidance.c: Include
	function-abi.h.
	* config/c6x/c6x.c: Likewise.

Comments

Jeff Law Sept. 29, 2019, 10:25 p.m. UTC | #1
On 9/11/19 1:16 PM, Richard Sandiford wrote:
> This patch makes regrename use a similar mask-and-clobber-set
> pair to IRA when tracking whether registers are clobbered by
> calls in a region.  Testing for a nonzero ABI mask is equivalent
> to testing for a register that crosses a call.
> 
> Since AArch64 and c6x use regrename.h, they need to be updated
> to include function-abi.h first.  AIUI this is preferred over
> including function-abi.h in regrename.h.
> 
> 
> 2019-09-11  Richard Sandiford  <richard.sandiford@arm.com>
> 
> gcc/
> 	* regrename.h (du_head::call_clobber_mask): New field.
> 	(du_head::need_caller_save_reg): Replace with...
> 	(du_head::call_abis): ...this new field.
> 	* regrename.c: Include function-abi.h.
> 	(call_clobbered_in_chain_p): New function.
> 	(check_new_reg_p): Use crtl->abi when deciding whether a register
> 	is free for use after RA.  Use call_clobbered_in_chain_p to test
> 	whether a candidate register would be clobbered by a call.
> 	(find_rename_reg): Don't add call-clobber conflicts here.
> 	(rename_chains): Check call_abis instead of need_caller_save_reg.
> 	(merge_chains): Update for changes to du_head.
> 	(build_def_use): Use call_insn_abi to get the ABI of the call insn
> 	target.  Record the ABI identifier in call_abis and the set of
> 	fully or partially clobbered registers in call_clobber_mask.
> 	Add fully-clobbered registers to hard_conflicts here rather
> 	than in find_rename_reg.
> 	* config/aarch64/cortex-a57-fma-steering.c: Include function-abi.h.
> 	(rename_single_chain): Check call_abis instead of need_caller_save_reg.
> 	* config/aarch64/falkor-tag-collision-avoidance.c: Include
> 	function-abi.h.
> 	* config/c6x/c6x.c: Likewise.
OK
jeff

Patch
diff mbox series

Index: gcc/regrename.h
===================================================================
--- gcc/regrename.h	2019-07-10 19:41:20.115948322 +0100
+++ gcc/regrename.h	2019-09-11 19:48:56.069616842 +0100
@@ -41,9 +41,12 @@  #define GCC_REGRENAME_H
   bitmap_head conflicts;
   /* Conflicts with untracked hard registers.  */
   HARD_REG_SET hard_conflicts;
+  /* Which registers are fully or partially clobbered by the calls that
+     the chain crosses.  */
+  HARD_REG_SET call_clobber_mask;
 
-  /* Nonzero if the chain crosses a call.  */
-  unsigned int need_caller_save_reg:1;
+  /* A bitmask of ABIs used by the calls that the chain crosses.  */
+  unsigned int call_abis : NUM_ABI_IDS;
   /* Nonzero if the register is used in a way that prevents renaming,
      such as the SET_DEST of a CALL_INSN or an asm operand that used
      to be a hard register.  */
Index: gcc/regrename.c
===================================================================
--- gcc/regrename.c	2019-09-11 19:47:32.898202916 +0100
+++ gcc/regrename.c	2019-09-11 19:48:56.069616842 +0100
@@ -33,6 +33,7 @@ 
 #include "addresses.h"
 #include "cfganal.h"
 #include "tree-pass.h"
+#include "function-abi.h"
 #include "regrename.h"
 
 /* This file implements the RTL register renaming pass of the compiler.  It is
@@ -303,6 +304,18 @@  merge_overlapping_regs (HARD_REG_SET *ps
     }
 }
 
+/* Return true if (reg:MODE REGNO) would be clobbered by a call covered
+   by THIS_HEAD.  */
+
+static bool
+call_clobbered_in_chain_p (du_head *this_head, machine_mode mode,
+			   unsigned int regno)
+{
+  return call_clobbered_in_region_p (this_head->call_abis,
+				     this_head->call_clobber_mask,
+				     mode, regno);
+}
+
 /* Check if NEW_REG can be the candidate register to rename for
    REG in THIS_HEAD chain.  THIS_UNAVAILABLE is a set of unavailable hard
    registers.  */
@@ -322,7 +335,7 @@  check_new_reg_p (int reg ATTRIBUTE_UNUSE
 	|| global_regs[new_reg + i]
 	/* Can't use regs which aren't saved by the prologue.  */
 	|| (! df_regs_ever_live_p (new_reg + i)
-	    && ! call_used_or_fixed_reg_p (new_reg + i))
+	    && ! crtl->abi->clobbers_full_reg_p (new_reg + i))
 #ifdef LEAF_REGISTERS
 	/* We can't use a non-leaf register if we're in a
 	   leaf function.  */
@@ -337,11 +350,8 @@  check_new_reg_p (int reg ATTRIBUTE_UNUSE
   for (tmp = this_head->first; tmp; tmp = tmp->next_use)
     if ((!targetm.hard_regno_mode_ok (new_reg, GET_MODE (*tmp->loc))
 	 && ! DEBUG_INSN_P (tmp->insn))
-	|| (this_head->need_caller_save_reg
-	    && ! (targetm.hard_regno_call_part_clobbered
-		  (0, reg, GET_MODE (*tmp->loc)))
-	    && (targetm.hard_regno_call_part_clobbered
-		(0, new_reg, GET_MODE (*tmp->loc)))))
+	|| call_clobbered_in_chain_p (this_head, GET_MODE (*tmp->loc),
+				      new_reg))
       return false;
 
   return true;
@@ -363,12 +373,6 @@  find_rename_reg (du_head_p this_head, en
   int pass;
   int best_new_reg = old_reg;
 
-  /* Further narrow the set of registers we can use for renaming.
-     If the chain needs a call-saved register, mark the call-used
-     registers as unavailable.  */
-  if (this_head->need_caller_save_reg)
-    *unavailable |= call_used_or_fixed_regs;
-
   /* Mark registers that overlap this chain's lifetime as unavailable.  */
   merge_overlapping_regs (unavailable, this_head);
 
@@ -499,7 +503,7 @@  rename_chains (void)
 	{
 	  fprintf (dump_file, "Register %s in insn %d",
 		   reg_names[reg], INSN_UID (this_head->first->insn));
-	  if (this_head->need_caller_save_reg)
+	  if (this_head->call_abis)
 	    fprintf (dump_file, " crosses a call");
 	}
 
@@ -680,7 +684,8 @@  merge_chains (du_head_p c1, du_head_p c2
   c1->hard_conflicts |= c2->hard_conflicts;
   bitmap_ior_into (&c1->conflicts, &c2->conflicts);
 
-  c1->need_caller_save_reg |= c2->need_caller_save_reg;
+  c1->call_clobber_mask |= c2->call_clobber_mask;
+  c1->call_abis |= c2->call_abis;
   c1->cannot_rename |= c2->cannot_rename;
 }
 
@@ -1834,9 +1839,14 @@  build_def_use (basic_block bb)
 	     requires a caller-saved reg.  */
 	  if (CALL_P (insn))
 	    {
+	      function_abi abi = call_insn_abi (insn);
 	      class du_head *p;
 	      for (p = open_chains; p; p = p->next_chain)
-		p->need_caller_save_reg = 1;
+		{
+		  p->call_abis |= (1 << abi.id ());
+		  p->call_clobber_mask |= abi.full_and_partial_reg_clobbers ();
+		  p->hard_conflicts |= abi.full_reg_clobbers ();
+		}
 	    }
 
 	  /* Step 5: Close open chains that overlap writes.  Similar to
Index: gcc/config/aarch64/cortex-a57-fma-steering.c
===================================================================
--- gcc/config/aarch64/cortex-a57-fma-steering.c	2019-09-09 18:59:26.352024447 +0100
+++ gcc/config/aarch64/cortex-a57-fma-steering.c	2019-09-11 19:48:56.065616870 +0100
@@ -37,6 +37,7 @@  #define INCLUDE_LIST
 #include "insn-attr.h"
 #include "context.h"
 #include "tree-pass.h"
+#include "function-abi.h"
 #include "regrename.h"
 #include "aarch64-protos.h"
 
@@ -281,7 +282,7 @@  rename_single_chain (du_head_p head, HAR
     {
       fprintf (dump_file, "Register %s in insn %d", reg_names[reg],
 	       INSN_UID (head->first->insn));
-      if (head->need_caller_save_reg)
+      if (head->call_abis)
 	fprintf (dump_file, " crosses a call");
     }
 
Index: gcc/config/aarch64/falkor-tag-collision-avoidance.c
===================================================================
--- gcc/config/aarch64/falkor-tag-collision-avoidance.c	2019-09-09 18:59:26.352024447 +0100
+++ gcc/config/aarch64/falkor-tag-collision-avoidance.c	2019-09-11 19:48:56.065616870 +0100
@@ -38,6 +38,7 @@  #define INCLUDE_LIST
 #include "optabs.h"
 #include "regs.h"
 #include "recog.h"
+#include "function-abi.h"
 #include "regrename.h"
 #include "print-rtl.h"
 
Index: gcc/config/c6x/c6x.c
===================================================================
--- gcc/config/c6x/c6x.c	2019-09-10 19:56:55.597105623 +0100
+++ gcc/config/c6x/c6x.c	2019-09-11 19:48:56.069616842 +0100
@@ -55,6 +55,7 @@  #define IN_TARGET_CODE 1
 #include "sel-sched.h"
 #include "debug.h"
 #include "hw-doloop.h"
+#include "function-abi.h"
 #include "regrename.h"
 #include "dumpfile.h"
 #include "builtins.h"