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[PTX] more register cleanups
- From: Nathan Sidwell <nathan at acm dot org>
- To: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Tue, 15 Dec 2015 15:49:16 -0500
- Subject: [PTX] more register cleanups
- Authentication-results: sourceware.org; auth=none
this patch uses reg_names array to emit register names, rather than have
knowledge scattered throughout the PTX backend. Also, converted
write_fn_proto_from_insn to use (renamed) write_arg_mode and (new)
write_return_mode. I also noticed we can use liveness information to determine
whether an outgoing static chain needs declaring.
nathan
2015-12-15 Nathan Sidwell <nathan@acm.org>
* config/nvptx/nvptx.c (write_one_arg): Rename to ...
(write_arg_mode): ... here. Update callers.
(write_arg): Rename to ...
(write__arg_type): ... here. Update callers.
(write_return_mode): New fn, broken out of ...
(write_return): ... here. Rename to ...
(write_return_type): ... here. Call it. Update callers.
(write_fn_proto_from_insn): Use write_arg_mode and
write_return_mode.
(init_frame): New fn.
(nvptx_declare_function_name): Call it for frame and varargs. Only
emit outgoing static chain, if it's live.
(nvptx_output_return): Use reg_names for return reg name.
(nvptx_output_call_insn): Likewise.
(nvptx_reorg): Mark unused hard regs too.
Index: config/nvptx/nvptx.c
===================================================================
--- config/nvptx/nvptx.c (revision 231662)
+++ config/nvptx/nvptx.c (working copy)
@@ -569,7 +569,8 @@ nvptx_static_chain (const_tree fndecl, b
copying to a specific hard register. */
static int
-write_one_arg (std::stringstream &s, int for_reg, int argno, machine_mode mode)
+write_arg_mode (std::stringstream &s, int for_reg, int argno,
+ machine_mode mode)
{
const char *ptx_type = nvptx_ptx_type_from_mode (mode, false);
@@ -598,7 +599,7 @@ write_one_arg (std::stringstream &s, int
}
/* Process function parameter TYPE to emit one or more PTX
- arguments. S, FOR_REG and ARGNO as for write_one_arg. PROTOTYPED
+ arguments. S, FOR_REG and ARGNO as for write_arg_mode. PROTOTYPED
is true, if this is a prototyped function, rather than an old-style
C declaration. Returns the next argument number to use.
@@ -606,8 +607,8 @@ write_one_arg (std::stringstream &s, int
parameter marshalling machinery. */
static int
-write_arg (std::stringstream &s, int for_reg, int argno,
- tree type, bool prototyped)
+write_arg_type (std::stringstream &s, int for_reg, int argno,
+ tree type, bool prototyped)
{
machine_mode mode = TYPE_MODE (type);
@@ -630,21 +631,35 @@ write_arg (std::stringstream &s, int for
mode = promote_arg (mode, prototyped);
if (split)
- argno = write_one_arg (s, for_reg, argno, mode);
+ argno = write_arg_mode (s, for_reg, argno, mode);
}
- return write_one_arg (s, for_reg, argno, mode);
+ return write_arg_mode (s, for_reg, argno, mode);
+}
+
+/* Emit a PTX return as a prototype or function prologue declaration
+ for MODE. */
+
+static void
+write_return_mode (std::stringstream &s, bool for_proto, machine_mode mode)
+{
+ const char *ptx_type = nvptx_ptx_type_from_mode (mode, false);
+ const char *pfx = "\t.reg";
+ const char *sfx = ";\n";
+
+ if (for_proto)
+ pfx = "(.param", sfx = "_out) ";
+
+ s << pfx << ptx_type << " " << reg_names[NVPTX_RETURN_REGNUM] << sfx;
}
/* Process a function return TYPE to emit a PTX return as a prototype
- or function prologue declaration. DECL_RESULT is the decl result
- of the function and needed for determining named result
- behaviour. Returns true if return is via an additional pointer
- parameter. The promotion behaviour here must match the regular GCC
- function return mashalling. */
+ or function prologue declaration. Returns true if return is via an
+ additional pointer parameter. The promotion behaviour here must
+ match the regular GCC function return mashalling. */
static bool
-write_return (std::stringstream &s, bool for_proto, tree type)
+write_return_type (std::stringstream &s, bool for_proto, tree type)
{
machine_mode mode = TYPE_MODE (type);
@@ -675,11 +690,7 @@ write_return (std::stringstream &s, bool
else
mode = promote_return (mode);
- const char *ptx_type = nvptx_ptx_type_from_mode (mode, false);
- if (for_proto)
- s << "(.param" << ptx_type << " %out_retval) ";
- else
- s << "\t.reg" << ptx_type << " %retval;\n";
+ write_return_mode (s, for_proto, mode);
return return_in_mem;
}
@@ -752,7 +763,7 @@ write_fn_proto (std::stringstream &s, bo
tree result_type = TREE_TYPE (fntype);
/* Declare the result. */
- bool return_in_mem = write_return (s, true, result_type);
+ bool return_in_mem = write_return_type (s, true, result_type);
s << name;
@@ -760,7 +771,7 @@ write_fn_proto (std::stringstream &s, bo
/* Emit argument list. */
if (return_in_mem)
- argno = write_arg (s, -1, argno, ptr_type_node, true);
+ argno = write_arg_type (s, -1, argno, ptr_type_node, true);
/* We get:
NULL in TYPE_ARG_TYPES, for old-style functions
@@ -779,19 +790,19 @@ write_fn_proto (std::stringstream &s, bo
{
tree type = prototyped ? TREE_VALUE (args) : TREE_TYPE (args);
- argno = write_arg (s, -1, argno, type, prototyped);
+ argno = write_arg_type (s, -1, argno, type, prototyped);
}
if (stdarg_p (fntype))
- argno = write_arg (s, -1, argno, ptr_type_node, true);
+ argno = write_arg_type (s, -1, argno, ptr_type_node, true);
if (DECL_STATIC_CHAIN (decl))
- argno = write_arg (s, -1, argno, ptr_type_node, true);
+ argno = write_arg_type (s, -1, argno, ptr_type_node, true);
if (!argno && strcmp (name, "main") == 0)
{
- argno = write_arg (s, -1, argno, integer_type_node, true);
- argno = write_arg (s, -1, argno, ptr_type_node, true);
+ argno = write_arg_type (s, -1, argno, integer_type_node, true);
+ argno = write_arg_type (s, -1, argno, ptr_type_node, true);
}
if (argno)
@@ -824,28 +835,19 @@ write_fn_proto_from_insn (std::stringstr
}
if (result != NULL_RTX)
- s << "(.param"
- << nvptx_ptx_type_from_mode (GET_MODE (result), false)
- << " %rval) ";
+ write_return_mode (s, true, GET_MODE (result));
s << name;
- const char *sep = " (";
int arg_end = XVECLEN (pat, 0);
for (int i = 1; i < arg_end; i++)
{
- /* We don't have to deal with mode splitting here, as that was
- already done when generating the call sequence. */
+ /* We don't have to deal with mode splitting & promotion here,
+ as that was already done when generating the call
+ sequence. */
machine_mode mode = GET_MODE (XEXP (XVECEXP (pat, 0, i), 0));
- s << sep
- << ".param"
- << nvptx_ptx_type_from_mode (mode, false)
- << " %arg"
- << i;
- if (mode == QImode || mode == HImode)
- s << "[1]";
- sep = ", ";
+ write_arg_mode (s, -1, i - 1, mode);
}
if (arg_end != 1)
s << ")";
@@ -914,6 +916,20 @@ nvptx_maybe_record_fnsym (rtx sym)
nvptx_record_needed_fndecl (decl);
}
+/* Emit a local array to hold some part of a conventional stack frame
+ and initialize REGNO to point to it. */
+
+static void
+init_frame (FILE *file, int regno, unsigned align, unsigned size)
+{
+ fprintf (file, "\t.reg.u%d %s;\n"
+ "\t.local.align %d .b8 %s_ar[%u];\n"
+ "\tcvta.local.u%d %s, %s_ar;\n",
+ POINTER_SIZE, reg_names[regno],
+ align, reg_names[regno], size ? size : 1,
+ POINTER_SIZE, reg_names[regno], reg_names[regno]);
+}
+
/* Emit code to initialize the REGNO predicate register to indicate
whether we are not lane zero on the NAME axis. */
@@ -944,9 +960,9 @@ nvptx_declare_function_name (FILE *file,
write_fn_proto (s, true, name, decl);
s << "{\n";
- bool return_in_mem = write_return (s, false, result_type);
+ bool return_in_mem = write_return_type (s, false, result_type);
if (return_in_mem)
- argno = write_arg (s, 0, argno, ptr_type_node, true);
+ argno = write_arg_type (s, 0, argno, ptr_type_node, true);
/* Declare and initialize incoming arguments. */
tree args = TYPE_ARG_TYPES (fntype);
@@ -961,20 +977,22 @@ nvptx_declare_function_name (FILE *file,
{
tree type = prototyped ? TREE_VALUE (args) : TREE_TYPE (args);
- argno = write_arg (s, 0, argno, type, prototyped);
+ argno = write_arg_type (s, 0, argno, type, prototyped);
}
if (stdarg_p (fntype))
- argno = write_arg (s, ARG_POINTER_REGNUM, argno, ptr_type_node, true);
+ argno = write_arg_type (s, ARG_POINTER_REGNUM, argno, ptr_type_node, true);
if (DECL_STATIC_CHAIN (decl))
- argno = write_arg (s, STATIC_CHAIN_REGNUM, argno, ptr_type_node, true);
+ argno = write_arg_type (s, STATIC_CHAIN_REGNUM, argno, ptr_type_node,
+ true);
fprintf (file, "%s", s.str().c_str());
- fprintf (file, "\t.reg.u%d %s;\n", GET_MODE_BITSIZE (Pmode),
- reg_names[OUTGOING_STATIC_CHAIN_REGNUM]);
-
+ if (regno_reg_rtx[OUTGOING_STATIC_CHAIN_REGNUM] != const0_rtx)
+ fprintf (file, "\t.reg.u%d %s;\n", GET_MODE_BITSIZE (Pmode),
+ reg_names[OUTGOING_STATIC_CHAIN_REGNUM]);
+
/* Declare the pseudos we have as ptx registers. */
int maxregs = max_reg_num ();
for (int i = LAST_VIRTUAL_REGISTER + 1; i < maxregs; i++)
@@ -992,35 +1010,16 @@ nvptx_declare_function_name (FILE *file,
}
}
- /* The only reason we might be using outgoing args is if we call a stdargs
- function. Allocate the space for this. If we called varargs functions
- without passing any variadic arguments, we'll see a reference to outargs
- even with a zero outgoing_args_size. */
- HOST_WIDE_INT sz = crtl->outgoing_args_size;
- if (sz == 0)
- sz = 1;
+ /* Declare a local var for outgoing varargs. */
if (cfun->machine->has_call_with_varargs)
- {
- fprintf (file, "\t.reg.u%d %%outargs;\n"
- "\t.local.align 8 .b8 %%outargs_ar["
- HOST_WIDE_INT_PRINT_DEC"];\n",
- BITS_PER_WORD, sz);
- fprintf (file, "\tcvta.local.u%d %%outargs, %%outargs_ar;\n",
- BITS_PER_WORD);
- }
+ init_frame (file, STACK_POINTER_REGNUM,
+ UNITS_PER_WORD, crtl->outgoing_args_size);
/* Declare a local variable for the frame. */
- sz = get_frame_size ();
- if (sz > 0 || cfun->machine->has_call_with_sc)
- {
- int alignment = crtl->stack_alignment_needed / BITS_PER_UNIT;
-
- fprintf (file, "\t.reg.u%d %%frame;\n"
- "\t.local.align %d .b8 %%farray[" HOST_WIDE_INT_PRINT_DEC"];\n",
- BITS_PER_WORD, alignment, sz == 0 ? 1 : sz);
- fprintf (file, "\tcvta.local.u%d %%frame, %%farray;\n",
- BITS_PER_WORD);
- }
+ HOST_WIDE_INT sz = get_frame_size ();
+ if (sz || cfun->machine->has_call_with_sc)
+ init_frame (file, FRAME_POINTER_REGNUM,
+ crtl->stack_alignment_needed / BITS_PER_UNIT, sz);
/* Emit axis predicates. */
if (cfun->machine->axis_predicate[0])
@@ -1040,8 +1039,10 @@ nvptx_output_return (void)
machine_mode mode = (machine_mode)cfun->machine->ret_reg_mode;
if (mode != VOIDmode)
- fprintf (asm_out_file, "\tst.param%s\t[%%out_retval], %%retval;\n",
- nvptx_ptx_type_from_mode (mode, false));
+ fprintf (asm_out_file, "\tst.param%s\t[%s_out], %s;\n",
+ nvptx_ptx_type_from_mode (mode, false),
+ reg_names[NVPTX_RETURN_REGNUM],
+ reg_names[NVPTX_RETURN_REGNUM]);
return "ret;";
}
@@ -1817,8 +1818,9 @@ nvptx_output_call_insn (rtx_insn *insn,
fprintf (asm_out_file, "\t{\n");
if (result != NULL)
- fprintf (asm_out_file, "\t\t.param%s %%retval_in;\n",
- nvptx_ptx_type_from_mode (GET_MODE (result), false));
+ fprintf (asm_out_file, "\t\t.param%s %s_in;\n",
+ nvptx_ptx_type_from_mode (GET_MODE (result), false),
+ reg_names[NVPTX_RETURN_REGNUM]);
/* Ensure we have a ptx declaration in the output if necessary. */
if (GET_CODE (callee) == SYMBOL_REF)
@@ -1857,8 +1859,8 @@ nvptx_output_call_insn (rtx_insn *insn,
fprintf (asm_out_file, "\t\tcall ");
if (result != NULL_RTX)
- fprintf (asm_out_file, "(%%retval_in), ");
-
+ fprintf (asm_out_file, "(%s_in), ", reg_names[NVPTX_RETURN_REGNUM]);
+
if (decl)
{
const char *name = get_fnname_from_decl (decl);
@@ -1897,7 +1899,18 @@ nvptx_output_call_insn (rtx_insn *insn,
trap, which it does grok. */
fprintf (asm_out_file, "\t\ttrap; // (noreturn)\n");
- return result != NULL_RTX ? "\tld.param%t0\t%0, [%%retval_in];\n\t}" : "}";
+ if (result)
+ {
+ static char rval[sizeof ("\tld.param%%t0\t%%0, [%%%s_in];\n\t}") + 8];
+
+ if (!rval[0])
+ /* We must escape the '%' that starts RETURN_REGNUM. */
+ sprintf (rval, "\tld.param%%t0\t%%0, [%%%s_in];\n\t}",
+ reg_names[NVPTX_RETURN_REGNUM]);
+ return rval;
+ }
+
+ return "}";
}
/* Implement TARGET_PRINT_OPERAND_PUNCT_VALID_P. */
@@ -3760,7 +3773,7 @@ nvptx_reorg (void)
/* Mark unused regs as unused. */
int max_regs = max_reg_num ();
- for (int i = LAST_VIRTUAL_REGISTER + 1; i < max_regs; i++)
+ for (int i = 0; i < max_regs; i++)
if (REG_N_SETS (i) == 0 && REG_N_REFS (i) == 0)
regno_reg_rtx[i] = const0_rtx;