From 6d852ffb43b111a39162135c95249e749c4e285b Mon Sep 17 00:00:00 2001
From: Max Filippov <jcmvbkbc@gmail.com>
Date: Thu, 6 Aug 2015 01:16:02 +0300
Subject: [PATCH] xtensa: add -mauto-litpools option

With support from assembler this option allows compiling huge functions,
where single literal pool at the beginning of a function may not be
reachable by L32R instructions at its end.

Currently assembler --auto-litpools option cannot deal with literals
used from multiple locations separated by more than 256 KBytes of code.
Don't turn constants into literals, instead use MOVI instruction to load
them into registers and let the assembler turn them into literals as
necessary.

2015-08-12  Max Filippov  <jcmvbkbc@gmail.com>
gcc/
	* config/xtensa/constraints.md (define_constraint "Y"): New
	constraint.
	* config/xtensa/elf.h (ASM_SPEC): Add m(no-)auto-litpools.
	* config/xtensa/linux.h (ASM_SPEC): Likewise.
	* config/xtensa/predicates.md (move_operand): Match constants
	and symbols in the presence of TARGET_AUTO_LITPOOLS.
	* config/xtensa/xtensa.c (xtensa_valid_move): Don't allow
	immediate references to TLS data.
	(xtensa_emit_move_sequence): Don't force constants to memory in
	the presence of TARGET_AUTO_LITPOOLS.
	(print_operand): Add 'y' format, same as default, but capable of
	printing SF mode constants as well.
	* config/xtensa/xtensa.md (movsi_internal, movhi_internal)
	(movsf_internal): Add movi pattern that loads literal.
	(movsf, movdf): Don't force constants to memory in the presence
	of TARGET_AUTO_LITPOOLS.
	(movdf_internal): Add 'Y' constraint.
	* config/xtensa/xtensa.opt (mauto-litpools): New option.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
Backported from: r226828
Changes to ChangeLogs and documentation are dropped.

 gcc/config/xtensa/constraints.md |  5 +++++
 gcc/config/xtensa/elf.h          |  4 +++-
 gcc/config/xtensa/linux.h        |  4 +++-
 gcc/config/xtensa/predicates.md  |  3 ++-
 gcc/config/xtensa/xtensa.c       | 19 ++++++++++++++++++-
 gcc/config/xtensa/xtensa.md      | 35 +++++++++++++++++++----------------
 gcc/config/xtensa/xtensa.opt     |  4 ++++
 7 files changed, 54 insertions(+), 20 deletions(-)

Index: b/gcc/config/xtensa/constraints.md
===================================================================
--- a/gcc/config/xtensa/constraints.md
+++ b/gcc/config/xtensa/constraints.md
@@ -111,6 +111,11 @@
  (and (match_code "const_int")
       (match_test "xtensa_mask_immediate (ival)")))
 
+(define_constraint "Y"
+ "A constant that can be used in relaxed MOVI instructions."
+ (and (match_code "const_int,const_double,const,symbol_ref,label_ref")
+      (match_test "TARGET_AUTO_LITPOOLS")))
+
 ;; Memory constraints.  Do not use define_memory_constraint here.  Doing so
 ;; causes reload to force some constants into the constant pool, but since
 ;; the Xtensa constant pool can only be accessed with L32R instructions, it
Index: b/gcc/config/xtensa/elf.h
===================================================================
--- a/gcc/config/xtensa/elf.h
+++ b/gcc/config/xtensa/elf.h
@@ -48,7 +48,9 @@
   %{mtarget-align:--target-align} \
   %{mno-target-align:--no-target-align} \
   %{mlongcalls:--longcalls} \
-  %{mno-longcalls:--no-longcalls}"
+  %{mno-longcalls:--no-longcalls} \
+  %{mauto-litpools:--auto-litpools} \
+  %{mno-auto-litpools:--no-auto-litpools}"
 
 #undef LIB_SPEC
 #define LIB_SPEC "-lc -lsim -lc -lhandlers-sim -lhal"
Index: b/gcc/config/xtensa/linux.h
===================================================================
--- a/gcc/config/xtensa/linux.h
+++ b/gcc/config/xtensa/linux.h
@@ -42,7 +42,9 @@
   %{mtarget-align:--target-align} \
   %{mno-target-align:--no-target-align} \
   %{mlongcalls:--longcalls} \
-  %{mno-longcalls:--no-longcalls}"
+  %{mno-longcalls:--no-longcalls} \
+  %{mauto-litpools:--auto-litpools} \
+  %{mno-auto-litpools:--no-auto-litpools}"
 
 #define GLIBC_DYNAMIC_LINKER "/lib/ld.so.1"
 
Index: b/gcc/config/xtensa/predicates.md
===================================================================
--- a/gcc/config/xtensa/predicates.md
+++ b/gcc/config/xtensa/predicates.md
@@ -142,7 +142,8 @@
 	       (match_test "GET_MODE_CLASS (mode) == MODE_INT
 			    && xtensa_simm12b (INTVAL (op))"))
 	  (and (match_code "const_int,const_double,const,symbol_ref,label_ref")
-	       (match_test "TARGET_CONST16 && CONSTANT_P (op)
+	       (match_test "(TARGET_CONST16 || TARGET_AUTO_LITPOOLS)
+			    && CONSTANT_P (op)
 			    && GET_MODE_SIZE (mode) % UNITS_PER_WORD == 0")))))
 
 ;; Accept the floating point constant 1 in the appropriate mode.
Index: b/gcc/config/xtensa/xtensa.c
===================================================================
--- a/gcc/config/xtensa/xtensa.c
+++ b/gcc/config/xtensa/xtensa.c
@@ -477,6 +477,9 @@
     {
       int dst_regnum = xt_true_regnum (operands[0]);
 
+      if (xtensa_tls_referenced_p (operands[1]))
+	return FALSE;
+
       /* The stack pointer can only be assigned with a MOVSP opcode.  */
       if (dst_regnum == STACK_POINTER_REGNUM)
 	return (mode == SImode
@@ -1044,7 +1047,7 @@
 	  return 1;
 	}
 
-      if (! TARGET_CONST16)
+      if (! TARGET_AUTO_LITPOOLS && ! TARGET_CONST16)
 	{
 	  src = force_const_mem (SImode, src);
 	  operands[1] = src;
@@ -2428,6 +2431,20 @@
 	}
       break;
 
+    case 'y':
+      if (GET_CODE (x) == CONST_DOUBLE &&
+	  GET_MODE (x) == SFmode)
+	{
+	  REAL_VALUE_TYPE r;
+	  long l;
+	  REAL_VALUE_FROM_CONST_DOUBLE (r, x);
+	  REAL_VALUE_TO_TARGET_SINGLE (r, l);
+	  fprintf (file, "0x%08lx", l);
+	  break;
+	}
+
+      /* fall through */
+
     default:
       if (GET_CODE (x) == REG || GET_CODE (x) == SUBREG)
 	fprintf (file, "%s", reg_names[xt_true_regnum (x)]);
Index: b/gcc/config/xtensa/xtensa.md
===================================================================
--- a/gcc/config/xtensa/xtensa.md
+++ b/gcc/config/xtensa/xtensa.md
@@ -799,8 +799,8 @@
 })
 
 (define_insn "movsi_internal"
-  [(set (match_operand:SI 0 "nonimmed_operand" "=D,D,D,D,R,R,a,q,a,W,a,a,U,*a,*A")
-	(match_operand:SI 1 "move_operand" "M,D,d,R,D,d,r,r,I,i,T,U,r,*A,*r"))]
+  [(set (match_operand:SI 0 "nonimmed_operand" "=D,D,D,D,R,R,a,q,a,a,W,a,a,U,*a,*A")
+	(match_operand:SI 1 "move_operand" "M,D,d,R,D,d,r,r,I,Y,i,T,U,r,*A,*r"))]
   "xtensa_valid_move (SImode, operands)"
   "@
    movi.n\t%0, %x1
@@ -812,15 +812,16 @@
    mov\t%0, %1
    movsp\t%0, %1
    movi\t%0, %x1
+   movi\t%0, %1
    const16\t%0, %t1\;const16\t%0, %b1
    %v1l32r\t%0, %1
    %v1l32i\t%0, %1
    %v0s32i\t%1, %0
    rsr\t%0, ACCLO
    wsr\t%1, ACCLO"
-  [(set_attr "type" "move,move,move,load,store,store,move,move,move,move,load,load,store,rsr,wsr")
+  [(set_attr "type" "move,move,move,load,store,store,move,move,move,move,move,load,load,store,rsr,wsr")
    (set_attr "mode"	"SI")
-   (set_attr "length"	"2,2,2,2,2,2,3,3,3,6,3,3,3,3,3")])
+   (set_attr "length"	"2,2,2,2,2,2,3,3,3,3,6,3,3,3,3,3")])
 
 ;; 16-bit Integer moves
 
@@ -834,21 +835,22 @@
 })
 
 (define_insn "movhi_internal"
-  [(set (match_operand:HI 0 "nonimmed_operand" "=D,D,a,a,a,U,*a,*A")
-	(match_operand:HI 1 "move_operand" "M,d,r,I,U,r,*A,*r"))]
+  [(set (match_operand:HI 0 "nonimmed_operand" "=D,D,a,a,a,a,U,*a,*A")
+	(match_operand:HI 1 "move_operand" "M,d,r,I,Y,U,r,*A,*r"))]
   "xtensa_valid_move (HImode, operands)"
   "@
    movi.n\t%0, %x1
    mov.n\t%0, %1
    mov\t%0, %1
    movi\t%0, %x1
+   movi\t%0, %1
    %v1l16ui\t%0, %1
    %v0s16i\t%1, %0
    rsr\t%0, ACCLO
    wsr\t%1, ACCLO"
-  [(set_attr "type"	"move,move,move,move,load,store,rsr,wsr")
+  [(set_attr "type"	"move,move,move,move,move,load,store,rsr,wsr")
    (set_attr "mode"	"HI")
-   (set_attr "length"	"2,2,3,3,3,3,3,3")])
+   (set_attr "length"	"2,2,3,3,3,3,3,3,3")])
 
 ;; 8-bit Integer moves
 
@@ -919,7 +921,7 @@
 	(match_operand:SF 1 "general_operand" ""))]
   ""
 {
-  if (!TARGET_CONST16 && CONSTANT_P (operands[1]))
+  if (!TARGET_CONST16 && !TARGET_AUTO_LITPOOLS && CONSTANT_P (operands[1]))
     operands[1] = force_const_mem (SFmode, operands[1]);
 
   if ((!register_operand (operands[0], SFmode)
@@ -934,8 +936,8 @@
 })
 
 (define_insn "movsf_internal"
-  [(set (match_operand:SF 0 "nonimmed_operand" "=f,f,U,D,D,R,a,f,a,W,a,a,U")
-	(match_operand:SF 1 "move_operand" "f,U,f,d,R,d,r,r,f,iF,T,U,r"))]
+  [(set (match_operand:SF 0 "nonimmed_operand" "=f,f,U,D,D,R,a,f,a,a,W,a,a,U")
+	(match_operand:SF 1 "move_operand" "f,U,f,d,R,d,r,r,f,Y,iF,T,U,r"))]
   "((register_operand (operands[0], SFmode)
      || register_operand (operands[1], SFmode))
     && !(FP_REG_P (xt_true_regnum (operands[0]))
@@ -950,13 +952,14 @@
    mov\t%0, %1
    wfr\t%0, %1
    rfr\t%0, %1
+   movi\t%0, %y1
    const16\t%0, %t1\;const16\t%0, %b1
    %v1l32r\t%0, %1
    %v1l32i\t%0, %1
    %v0s32i\t%1, %0"
-  [(set_attr "type"	"farith,fload,fstore,move,load,store,move,farith,farith,move,load,load,store")
+  [(set_attr "type"	"farith,fload,fstore,move,load,store,move,farith,farith,move,move,load,load,store")
    (set_attr "mode"	"SF")
-   (set_attr "length"	"3,3,3,2,2,2,3,3,3,6,3,3,3")])
+   (set_attr "length"	"3,3,3,2,2,2,3,3,3,3,6,3,3,3")])
 
 (define_insn "*lsiu"
   [(set (match_operand:SF 0 "register_operand" "=f")
@@ -997,7 +1000,7 @@
 	(match_operand:DF 1 "general_operand" ""))]
   ""
 {
-  if (CONSTANT_P (operands[1]) && !TARGET_CONST16)
+  if (CONSTANT_P (operands[1]) && !TARGET_CONST16 && !TARGET_AUTO_LITPOOLS)
     operands[1] = force_const_mem (DFmode, operands[1]);
 
   if (!register_operand (operands[0], DFmode)
@@ -1008,8 +1011,8 @@
 })
 
 (define_insn_and_split "movdf_internal"
-  [(set (match_operand:DF 0 "nonimmed_operand" "=a,W,a,a,U")
-	(match_operand:DF 1 "move_operand" "r,iF,T,U,r"))]
+  [(set (match_operand:DF 0 "nonimmed_operand" "=a,a,W,a,a,U")
+	(match_operand:DF 1 "move_operand" "r,Y,iF,T,U,r"))]
   "register_operand (operands[0], DFmode)
    || register_operand (operands[1], DFmode)"
   "#"
Index: b/gcc/config/xtensa/xtensa.opt
===================================================================
--- a/gcc/config/xtensa/xtensa.opt
+++ b/gcc/config/xtensa/xtensa.opt
@@ -38,6 +38,10 @@
 Target
 Intersperse literal pools with code in the text section
 
+mauto-litpools
+Target Report Mask(AUTO_LITPOOLS)
+Relax literals in assembler and place them automatically in the text section
+
 mserialize-volatile
 Target Report Mask(SERIALIZE_VOLATILE)
 -mno-serialize-volatile	Do not serialize volatile memory references with MEMW instructions