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* [gcc r14-5637] [APX PPX] Support Intel APX PPX
@ 2023-11-21  8:01 Hongyu Wang
  0 siblings, 0 replies; only message in thread
From: Hongyu Wang @ 2023-11-21  8:01 UTC (permalink / raw)
  To: gcc-cvs

https://gcc.gnu.org/g:7ad308bd4cca871e7509a5eeaef83ee68678820f

commit r14-5637-g7ad308bd4cca871e7509a5eeaef83ee68678820f
Author: Hongyu Wang <hongyu.wang@intel.com>
Date:   Thu Nov 16 15:18:07 2023 +0800

    [APX PPX] Support Intel APX PPX
    
    PPX stands for Push-Pop Acceleration. PUSH/PUSH2 and its corresponding POP
    can be marked with a 1-bit hint to indicate that the POP reads the
    value written by the PUSH from the stack. The processor tracks these marked
    instructions internally and fast-forwards register data between
    matching PUSH and POP instructions, without going through memory or
    through the training loop of the Fast Store Forwarding Predictor (FSFP).
    This feature can also be adopted to PUSH2/POP2.
    
    For GCC, we emit explicit suffix 'p' (paired) to indicate the push/pop
    pair are marked with PPX hint. To separate form original push/pop, we
    add an UNSPEC on top of those PUSH/POP patterns.
    
    In the first implementation we only emit them under prologue/epilogue
    when saving/restoring callee-saved registers to make sure push/pop are
    paired. So an extra flag was added to check if PPX insns can be emitted
    for those register save/restore interfaces.
    
    The PPX hint is purely a performance hint. If the 'p' suffix is not
    emitted for paired push/pop, the PPX optimization will be disabled,
    while program sematic will not be affected at all.
    
    gcc/ChangeLog:
    
            * config/i386/i386-expand.h (gen_push): Add default bool
            parameter.
            (gen_pop): Likewise.
            * config/i386/i386-opts.h (enum apx_features): Add apx_ppx, add
            it to apx_all.
            * config/i386/i386.cc (ix86_emit_restore_reg_using_pop): Add
            ppx_p parameter for function declaration.
            (gen_push2): Add ppx_p parameter, emit push2p if ppx_p is true.
            (gen_push): Likewise.
            (ix86_emit_restore_reg_using_pop2): Likewise for pop2p.
            (ix86_emit_save_regs): Emit pushp/push2p under TARGET_APX_PPX.
            (ix86_emit_restore_reg_using_pop): Add ppx_p, emit popp insn
            and adjust cfi when ppx_p is ture.
            (ix86_emit_restore_reg_using_pop2): Add ppx_p and parse to its
            callee.
            (ix86_emit_restore_regs_using_pop2): Likewise.
            (ix86_expand_epilogue): Parse TARGET_APX_PPX to
            ix86_emit_restore_reg_using_pop.
            * config/i386/i386.h (TARGET_APX_PPX): New.
            * config/i386/i386.md (UNSPEC_APX_PPX): New unspec.
            (pushp_di): New define_insn.
            (popp_di): Likewise.
            (push2p_di): Likewise.
            (pop2p_di): Likewise.
            * config/i386/i386.opt: Add apx_ppx enum.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.target/i386/apx-interrupt-1.c: Adjust option to restrict them
            under certain subfeatures.
            * gcc.target/i386/apx-push2pop2-1.c: Likewise.
            * gcc.target/i386/apx-push2pop2_force_drap-1.c: Likewise.
            * gcc.target/i386/apx-push2pop2_interrupt-1.c: Likewise.
            * gcc.target/i386/apx-ppx-1.c: New test.

Diff:
---
 gcc/config/i386/i386-expand.h                      |  4 +-
 gcc/config/i386/i386-opts.h                        |  3 +-
 gcc/config/i386/i386.cc                            | 70 +++++++++++++---------
 gcc/config/i386/i386.h                             |  1 +
 gcc/config/i386/i386.md                            | 45 +++++++++++++-
 gcc/config/i386/i386.opt                           |  3 +
 gcc/testsuite/gcc.target/i386/apx-interrupt-1.c    |  2 +-
 gcc/testsuite/gcc.target/i386/apx-ppx-1.c          |  9 +++
 gcc/testsuite/gcc.target/i386/apx-push2pop2-1.c    |  2 +-
 .../gcc.target/i386/apx-push2pop2_force_drap-1.c   |  2 +-
 .../gcc.target/i386/apx-push2pop2_interrupt-1.c    |  2 +-
 11 files changed, 107 insertions(+), 36 deletions(-)

diff --git a/gcc/config/i386/i386-expand.h b/gcc/config/i386/i386-expand.h
index 1ea789c4c3a..997cb7db059 100644
--- a/gcc/config/i386/i386-expand.h
+++ b/gcc/config/i386/i386-expand.h
@@ -44,9 +44,9 @@ void ix86_emit_binop (enum rtx_code code, machine_mode mode, rtx dst, rtx src);
 enum calling_abi ix86_function_abi (const_tree fndecl);
 bool ix86_function_ms_hook_prologue (const_tree fn);
 void warn_once_call_ms2sysv_xlogues (const char *feature);
-rtx gen_push (rtx arg);
+rtx gen_push (rtx arg, bool = false);
 rtx gen_pushfl (void);
-rtx gen_pop (rtx arg);
+rtx gen_pop (rtx arg, bool = false);
 rtx gen_popfl (void);
 rtx ix86_expand_builtin (tree exp, rtx target, rtx subtarget,
 			 machine_mode mode, int ignore);
diff --git a/gcc/config/i386/i386-opts.h b/gcc/config/i386/i386-opts.h
index 2ec76a16bce..4d293edb399 100644
--- a/gcc/config/i386/i386-opts.h
+++ b/gcc/config/i386/i386-opts.h
@@ -139,7 +139,8 @@ enum apx_features {
   apx_egpr = 1 << 0,
   apx_push2pop2 = 1 << 1,
   apx_ndd = 1 << 2,
-  apx_all = apx_egpr | apx_push2pop2 | apx_ndd,
+  apx_ppx = 1 << 3,
+  apx_all = apx_egpr | apx_push2pop2 | apx_ndd | apx_ppx,
 };
 
 #endif
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 683ac643bc8..bd340582a33 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -105,7 +105,7 @@ along with GCC; see the file COPYING3.  If not see
 static rtx legitimize_dllimport_symbol (rtx, bool);
 static rtx legitimize_pe_coff_extern_decl (rtx, bool);
 static void ix86_print_operand_address_as (FILE *, rtx, addr_space_t, bool);
-static void ix86_emit_restore_reg_using_pop (rtx);
+static void ix86_emit_restore_reg_using_pop (rtx, bool = false);
 
 
 #ifndef CHECK_STACK_LIMIT
@@ -6448,7 +6448,7 @@ output_set_got (rtx dest, rtx label)
 /* Generate an "push" pattern for input ARG.  */
 
 rtx
-gen_push (rtx arg)
+gen_push (rtx arg, bool ppx_p)
 {
   struct machine_function *m = cfun->machine;
 
@@ -6459,10 +6459,10 @@ gen_push (rtx arg)
   if (REG_P (arg) && GET_MODE (arg) != word_mode)
     arg = gen_rtx_REG (word_mode, REGNO (arg));
 
-  return gen_rtx_SET (gen_rtx_MEM (word_mode,
-				   gen_rtx_PRE_DEC (Pmode,
-						    stack_pointer_rtx)),
-		      arg);
+  rtx stack = gen_rtx_MEM (word_mode,
+			   gen_rtx_PRE_DEC (Pmode,
+					    stack_pointer_rtx));
+  return ppx_p ? gen_pushp_di (stack, arg) : gen_rtx_SET (stack, arg);
 }
 
 rtx
@@ -6486,15 +6486,16 @@ gen_pushfl (void)
 /* Generate an "pop" pattern for input ARG.  */
 
 rtx
-gen_pop (rtx arg)
+gen_pop (rtx arg, bool ppx_p)
 {
   if (REG_P (arg) && GET_MODE (arg) != word_mode)
     arg = gen_rtx_REG (word_mode, REGNO (arg));
 
-  return gen_rtx_SET (arg,
-		      gen_rtx_MEM (word_mode,
-				   gen_rtx_POST_INC (Pmode,
-						     stack_pointer_rtx)));
+  rtx stack = gen_rtx_MEM (word_mode,
+			   gen_rtx_POST_INC (Pmode,
+					     stack_pointer_rtx));
+
+  return ppx_p ? gen_popp_di (arg, stack) : gen_rtx_SET (arg, stack);
 }
 
 rtx
@@ -6512,7 +6513,7 @@ gen_popfl (void)
 
 /* Generate a "push2" pattern for input ARG.  */
 rtx
-gen_push2 (rtx mem, rtx reg1, rtx reg2)
+gen_push2 (rtx mem, rtx reg1, rtx reg2, bool ppx_p = false)
 {
   struct machine_function *m = cfun->machine;
   const int offset = UNITS_PER_WORD * 2;
@@ -6527,7 +6528,8 @@ gen_push2 (rtx mem, rtx reg1, rtx reg2)
   if (REG_P (reg2) && GET_MODE (reg2) != word_mode)
     reg2 = gen_rtx_REG (word_mode, REGNO (reg2));
 
-  return gen_push2_di (mem, reg1, reg2);
+  return ppx_p ? gen_push2p_di (mem, reg1, reg2):
+		 gen_push2_di (mem, reg1, reg2);
 }
 
 /* Return >= 0 if there is an unused call-clobbered register available
@@ -7369,7 +7371,8 @@ ix86_emit_save_regs (void)
       for (regno = FIRST_PSEUDO_REGISTER - 1; regno >= 0; regno--)
 	if (GENERAL_REGNO_P (regno) && ix86_save_reg (regno, true, true))
 	  {
-	    insn = emit_insn (gen_push (gen_rtx_REG (word_mode, regno)));
+	    insn = emit_insn (gen_push (gen_rtx_REG (word_mode, regno),
+					TARGET_APX_PPX));
 	    RTX_FRAME_RELATED_P (insn) = 1;
 	  }
     }
@@ -7399,7 +7402,8 @@ ix86_emit_save_regs (void)
 						 gen_rtx_REG (word_mode,
 							      regno_list[0]),
 						 gen_rtx_REG (word_mode,
-							      regno_list[1])));
+							      regno_list[1]),
+						 TARGET_APX_PPX));
 		    RTX_FRAME_RELATED_P (insn) = 1;
 		    rtx dwarf = gen_rtx_SEQUENCE (VOIDmode, rtvec_alloc (3));
 
@@ -7431,7 +7435,8 @@ ix86_emit_save_regs (void)
 	      }
 	    else
 	      {
-		insn = emit_insn (gen_push (gen_rtx_REG (word_mode, regno)));
+		insn = emit_insn (gen_push (gen_rtx_REG (word_mode, regno),
+					    TARGET_APX_PPX));
 		RTX_FRAME_RELATED_P (insn) = 1;
 		aligned = true;
 	      }
@@ -7439,7 +7444,8 @@ ix86_emit_save_regs (void)
       if (loaded_regnum == 1)
 	{
 	  insn = emit_insn (gen_push (gen_rtx_REG (word_mode,
-						   regno_list[0])));
+						   regno_list[0]),
+				      TARGET_APX_PPX));
 	  RTX_FRAME_RELATED_P (insn) = 1;
 	}
     }
@@ -9268,13 +9274,13 @@ ix86_expand_prologue (void)
     emit_insn (gen_prologue_use (stack_pointer_rtx));
 }
 
-/* Emit code to restore REG using a POP insn.  */
+/* Emit code to restore REG using a POP or POPP insn.  */
 
 static void
-ix86_emit_restore_reg_using_pop (rtx reg)
+ix86_emit_restore_reg_using_pop (rtx reg, bool ppx_p)
 {
   struct machine_function *m = cfun->machine;
-  rtx_insn *insn = emit_insn (gen_pop (reg));
+  rtx_insn *insn = emit_insn (gen_pop (reg, ppx_p));
 
   ix86_add_cfa_restore_note (insn, reg, m->fs.sp_offset);
   m->fs.sp_offset -= UNITS_PER_WORD;
@@ -9328,14 +9334,19 @@ ix86_emit_restore_reg_using_pop (rtx reg)
 
 /* Emit code to restore REG using a POP2 insn.  */
 static void
-ix86_emit_restore_reg_using_pop2 (rtx reg1, rtx reg2)
+ix86_emit_restore_reg_using_pop2 (rtx reg1, rtx reg2, bool ppx_p = false)
 {
   struct machine_function *m = cfun->machine;
   const int offset = UNITS_PER_WORD * 2;
+  rtx_insn *insn;
 
   rtx mem = gen_rtx_MEM (TImode, gen_rtx_POST_INC (Pmode,
 						   stack_pointer_rtx));
-  rtx_insn *insn = emit_insn (gen_pop2_di (reg1, mem, reg2));
+
+  if (ppx_p)
+    insn = emit_insn (gen_pop2p_di (reg1, mem, reg2));
+  else
+    insn = emit_insn (gen_pop2_di (reg1, mem, reg2));
 
   RTX_FRAME_RELATED_P (insn) = 1;
 
@@ -9397,13 +9408,13 @@ ix86_emit_restore_reg_using_pop2 (rtx reg1, rtx reg2)
 /* Emit code to restore saved registers using POP insns.  */
 
 static void
-ix86_emit_restore_regs_using_pop (void)
+ix86_emit_restore_regs_using_pop (bool ppx_p)
 {
   unsigned int regno;
 
   for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
     if (GENERAL_REGNO_P (regno) && ix86_save_reg (regno, false, true))
-      ix86_emit_restore_reg_using_pop (gen_rtx_REG (word_mode, regno));
+      ix86_emit_restore_reg_using_pop (gen_rtx_REG (word_mode, regno), ppx_p);
 }
 
 /* Emit code to restore saved registers using POP2 insns.  */
@@ -9432,20 +9443,23 @@ ix86_emit_restore_regs_using_pop2 (void)
 		ix86_emit_restore_reg_using_pop2 (gen_rtx_REG (word_mode,
 							       regno_list[0]),
 						  gen_rtx_REG (word_mode,
-							       regno_list[1]));
+							       regno_list[1]),
+						  TARGET_APX_PPX);
 		loaded_regnum = 0;
 		regno_list[0] = regno_list[1] = -1;
 	      }
 	  }
 	else
 	  {
-	    ix86_emit_restore_reg_using_pop (gen_rtx_REG (word_mode, regno));
+	    ix86_emit_restore_reg_using_pop (gen_rtx_REG (word_mode, regno),
+					     TARGET_APX_PPX);
 	    aligned = true;
 	  }
       }
 
   if (loaded_regnum == 1)
-    ix86_emit_restore_reg_using_pop (gen_rtx_REG (word_mode, regno_list[0]));
+    ix86_emit_restore_reg_using_pop (gen_rtx_REG (word_mode, regno_list[0]),
+				     TARGET_APX_PPX);
 }
 
 /* Emit code and notes for the LEAVE instruction.  If insn is non-null,
@@ -9990,7 +10004,7 @@ ix86_expand_epilogue (int style)
       if (TARGET_APX_PUSH2POP2 && m->func_type == TYPE_NORMAL)
 	ix86_emit_restore_regs_using_pop2 ();
       else
-	ix86_emit_restore_regs_using_pop ();
+	ix86_emit_restore_regs_using_pop (TARGET_APX_PPX);
     }
 
   /* If we used a stack pointer and haven't already got rid of it,
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index 6b27f486274..9c74b3ebd90 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -54,6 +54,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #define TARGET_APX_EGPR (ix86_apx_features & apx_egpr)
 #define TARGET_APX_PUSH2POP2 (ix86_apx_features & apx_push2pop2)
 #define TARGET_APX_NDD (ix86_apx_features & apx_ndd)
+#define TARGET_APX_PPX (ix86_apx_features & apx_ppx)
 
 #include "config/vxworks-dummy.h"
 
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 1b5a794b9e5..03e4ddd3037 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -210,10 +210,13 @@
   ;; For insn_callee_abi:
   UNSPEC_CALLEE_ABI
 
-  ;; For PUSH2/POP2 support
+  ;; For APX PUSH2/POP2 support
   UNSPEC_APXPUSH2
   UNSPEC_APXPOP2_LOW
   UNSPEC_APXPOP2_HIGH
+
+  ;; For APX PPX support
+  UNSPEC_APX_PPX
 ])
 
 (define_c_enum "unspecv" [
@@ -3785,6 +3788,46 @@
   [(set_attr "mode" "TI")
    (set_attr "prefix" "evex")])
 
+(define_insn "pushp_di"
+  [(set (match_operand:DI 0 "push_operand" "=<")
+	(match_operand:DI 1 "register_operand" "r"))
+   (unspec:DI [(const_int 0)] UNSPEC_APX_PPX)]
+  "TARGET_64BIT"
+  "pushp\t%1"
+  [(set_attr "mode" "DI")])
+
+(define_insn "popp_di"
+  [(set (match_operand:DI 0 "register_operand" "=r")
+	(match_operand:DI 1 "pop_operand" ">"))
+   (unspec:DI [(const_int 0)] UNSPEC_APX_PPX)]
+  "TARGET_APX_PPX"
+  "popp\t%0"
+  [(set_attr "mode" "DI")])
+
+(define_insn "push2p_di"
+  [(set (match_operand:TI 0 "push_operand" "=<")
+	(unspec:TI [(match_operand:DI 1 "register_operand" "r")
+		    (match_operand:DI 2 "register_operand" "r")]
+		    UNSPEC_APXPUSH2))
+   (unspec:DI [(const_int 0)] UNSPEC_APX_PPX)]
+  "TARGET_APX_PUSH2POP2 && TARGET_APX_PPX"
+  "push2p\t%1, %2"
+  [(set_attr "mode" "TI")
+   (set_attr "type" "multi")
+   (set_attr "prefix" "evex")])
+
+(define_insn "pop2p_di"
+  [(parallel [(set (match_operand:DI 0 "register_operand" "=r")
+		   (unspec:DI [(match_operand:TI 1 "pop_operand" ">")]
+			      UNSPEC_APXPOP2_LOW))
+	      (set (match_operand:DI 2 "register_operand" "=r")
+		   (unspec:DI [(const_int 0)] UNSPEC_APXPOP2_HIGH))
+	      (unspec:DI [(const_int 0)] UNSPEC_APX_PPX)])]
+  "TARGET_APX_PUSH2POP2 && TARGET_APX_PPX"
+  "pop2p\t%0, %2"
+  [(set_attr "mode" "TI")
+   (set_attr "prefix" "evex")])
+
 (define_insn "*pushsf_rex64"
   [(set (match_operand:SF 0 "push_operand" "=X,X,X")
 	(match_operand:SF 1 "nonmemory_no_elim_operand" "f,rF,v"))]
diff --git a/gcc/config/i386/i386.opt b/gcc/config/i386/i386.opt
index b81c968876e..b2edfac0b2a 100644
--- a/gcc/config/i386/i386.opt
+++ b/gcc/config/i386/i386.opt
@@ -1348,6 +1348,9 @@ Enum(apx_features) String(push2pop2) Value(apx_push2pop2) Set(3)
 EnumValue
 Enum(apx_features) String(ndd) Value(apx_ndd) Set(4)
 
+EnumValue
+Enum(apx_features) String(ppx) Value(apx_ppx) Set(5)
+
 EnumValue
 Enum(apx_features) String(all) Value(apx_all) Set(1)
 
diff --git a/gcc/testsuite/gcc.target/i386/apx-interrupt-1.c b/gcc/testsuite/gcc.target/i386/apx-interrupt-1.c
index 5f732d3e316..ffcb8fce71c 100644
--- a/gcc/testsuite/gcc.target/i386/apx-interrupt-1.c
+++ b/gcc/testsuite/gcc.target/i386/apx-interrupt-1.c
@@ -1,5 +1,5 @@
 /* { dg-do compile { target { ! ia32 } } } */
-/* { dg-options "-mapxf -m64 -O2 -mgeneral-regs-only -mno-cld -mno-push-args -maccumulate-outgoing-args" } */
+/* { dg-options "-mapx-features=egpr -m64 -O2 -mgeneral-regs-only -mno-cld -mno-push-args -maccumulate-outgoing-args" } */
 /* { dg-skip-if "does not emit .cfi_xxx" "*-*-darwin*" } */
 
 extern void foo (void *) __attribute__ ((interrupt));
diff --git a/gcc/testsuite/gcc.target/i386/apx-ppx-1.c b/gcc/testsuite/gcc.target/i386/apx-ppx-1.c
new file mode 100644
index 00000000000..e9a595381e3
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/apx-ppx-1.c
@@ -0,0 +1,9 @@
+/* { dg-do compile { target { ! ia32 } } } */
+/* { dg-options "-O2 -mapx-features=egpr,push2pop2,ppx" } */
+
+#include "apx-push2pop2-1.c"
+
+/* { dg-final { scan-assembler "pushp" } } */
+/* { dg-final { scan-assembler "popp" } } */
+/* { dg-final { scan-assembler "push2p" } } */
+/* { dg-final { scan-assembler "pop2p" } } */
diff --git a/gcc/testsuite/gcc.target/i386/apx-push2pop2-1.c b/gcc/testsuite/gcc.target/i386/apx-push2pop2-1.c
index 089941d3726..c53112758a5 100644
--- a/gcc/testsuite/gcc.target/i386/apx-push2pop2-1.c
+++ b/gcc/testsuite/gcc.target/i386/apx-push2pop2-1.c
@@ -1,5 +1,5 @@
 /* { dg-do compile { target { ! ia32 } } } */
-/* { dg-options "-O2 -mapxf" } */
+/* { dg-options "-O2 -mapx-features=push2pop2" } */
 /* { dg-skip-if "does not emit .cfi_xxx" "*-*-darwin*" } */
 
 extern int bar (int);
diff --git a/gcc/testsuite/gcc.target/i386/apx-push2pop2_force_drap-1.c b/gcc/testsuite/gcc.target/i386/apx-push2pop2_force_drap-1.c
index 656ca91391a..022113bb1e2 100644
--- a/gcc/testsuite/gcc.target/i386/apx-push2pop2_force_drap-1.c
+++ b/gcc/testsuite/gcc.target/i386/apx-push2pop2_force_drap-1.c
@@ -1,5 +1,5 @@
 /* { dg-do compile { target { ! ia32 } } } */
-/* { dg-options "-O2 -mapxf -mforce-drap" } */
+/* { dg-options "-O2 -mapx-features=push2pop2 -mforce-drap" } */
 /* { dg-skip-if "does not emit .cfi_xxx" "*-*-darwin*" } */
 
 #include "apx-push2pop2-1.c"
diff --git a/gcc/testsuite/gcc.target/i386/apx-push2pop2_interrupt-1.c b/gcc/testsuite/gcc.target/i386/apx-push2pop2_interrupt-1.c
index 747f7aaf191..a5b46893208 100644
--- a/gcc/testsuite/gcc.target/i386/apx-push2pop2_interrupt-1.c
+++ b/gcc/testsuite/gcc.target/i386/apx-push2pop2_interrupt-1.c
@@ -1,5 +1,5 @@
 /* { dg-do compile { target { ! ia32 } } } */
-/* { dg-options "-O2 -mapxf -mgeneral-regs-only -mno-cld -mno-push-args -maccumulate-outgoing-args" } */
+/* { dg-options "-O2 -mapx-features=egpr,push2pop2 -mgeneral-regs-only -mno-cld -mno-push-args -maccumulate-outgoing-args" } */
 
 extern void foo (void *) __attribute__ ((interrupt));

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2023-11-21  8:01 [gcc r14-5637] [APX PPX] Support Intel APX PPX Hongyu Wang

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