+2003-02-15 Roger Sayle <roger@eyesopen.com>
+
+ * config/i386/i386.c (x86_ext_80387_constants): Use 80387 insns
+ to load mathematical constants on K6, Athlon, Pentium 4 and PPro.
+ (ext_80387_constants_table): Global table of 80387 special constants
+ guarded by ext_80387_constants_init flag when not initialized.
+ (init_ext_80387_constants): New function to initialize this table.
+ (standard_80387_constant_p): Extend to recognize extra 80387
+ constants, in XFmode, on processors where this is a win.
+ (standard_80387_constant_opcode): New function to return the
+ opcode associated with standard_80387_constant_p.
+ (standard_80387_constant_rtx): New function to return the XFmode
+ CONST_DOUBLE associated with standard_80387_constant_p.
+ (ix86_rtx_costs): Give the new constants the same cost as 1.0.
+
+ * config/i386/i386-protos.h (standard_80387_constant_opcode):
+ Prototype here.
+ (standard_80387_constant_rtx): Likewise.
+
+ * config/i386/i386.md (*movsf1, *movsf1_nointerunit, *movdf_nointeger,
+ *movdf_integer, *movxf_nointeger, *movtf_nointeger, *movxf_integer,
+ *movtf_integer): Simplify using new standard_80387_constant_opcode.
+
2003-02-15 Geoffrey Keating <geoffk@apple.com>
* doc/invoke.texi (Optimize Options): Correct @option syntax.
const int x86_use_ffreep = m_ATHLON_K8;
const int x86_rep_movl_optimal = m_386 | m_PENT | m_PPRO | m_K6;
const int x86_inter_unit_moves = ~(m_ATHLON_K8);
+const int x86_ext_80387_constants = m_K6 | m_ATHLON | m_PENT4 | m_PPRO;
/* In case the average insn count for single function invocation is
lower than this constant, emit fast (but longer) prologue and
const int *, int));
static enum x86_64_reg_class merge_classes PARAMS ((enum x86_64_reg_class,
enum x86_64_reg_class));
+
+/* Table of constants used by fldpi, fldln2, etc... */
+static REAL_VALUE_TYPE ext_80387_constants_table [5];
+static bool ext_80387_constants_init = 0;
+static void init_ext_80387_constants PARAMS ((void));
\f
/* Initialize the GCC target structure. */
#undef TARGET_ATTRIBUTE_TABLE
return 1;
}
\f
+/* Initialize the table of extra 80387 mathematical constants. */
+
+static void
+init_ext_80387_constants ()
+{
+ static const char * cst[5] =
+ {
+ "0.3010299956639811952256464283594894482", /* 0: fldlg2 */
+ "0.6931471805599453094286904741849753009", /* 1: fldln2 */
+ "1.4426950408889634073876517827983434472", /* 2: fldl2e */
+ "3.3219280948873623478083405569094566090", /* 3: fldl2t */
+ "3.1415926535897932385128089594061862044", /* 4: fldpi */
+ };
+ int i;
+
+ for (i = 0; i < 5; i++)
+ {
+ real_from_string (&ext_80387_constants_table[i], cst[i]);
+ /* Ensure each constant is rounded to XFmode precision. */
+ real_convert (&ext_80387_constants_table[i], XFmode,
+ &ext_80387_constants_table[i]);
+ }
+
+ ext_80387_constants_init = 1;
+}
+
/* Return true if the constant is something that can be loaded with
- a special instruction. Only handle 0.0 and 1.0; others are less
- worthwhile. */
+ a special instruction. */
int
standard_80387_constant_p (x)
{
if (GET_CODE (x) != CONST_DOUBLE || !FLOAT_MODE_P (GET_MODE (x)))
return -1;
- /* Note that on the 80387, other constants, such as pi, that we should support
- too. On some machines, these are much slower to load as standard constant,
- than to load from doubles in memory. */
+
if (x == CONST0_RTX (GET_MODE (x)))
return 1;
if (x == CONST1_RTX (GET_MODE (x)))
return 2;
+
+ /* For XFmode constants, try to find a special 80387 instruction on
+ those CPUs that benefit from them. */
+ if (GET_MODE (x) == XFmode
+ && x86_ext_80387_constants & CPUMASK)
+ {
+ REAL_VALUE_TYPE r;
+ int i;
+
+ if (! ext_80387_constants_init)
+ init_ext_80387_constants ();
+
+ REAL_VALUE_FROM_CONST_DOUBLE (r, x);
+ for (i = 0; i < 5; i++)
+ if (real_identical (&r, &ext_80387_constants_table[i]))
+ return i + 3;
+ }
+
return 0;
}
+/* Return the opcode of the special instruction to be used to load
+ the constant X. */
+
+const char *
+standard_80387_constant_opcode (x)
+ rtx x;
+{
+ switch (standard_80387_constant_p (x))
+ {
+ case 1:
+ return "fldz";
+ case 2:
+ return "fld1";
+ case 3:
+ return "fldlg2";
+ case 4:
+ return "fldln2";
+ case 5:
+ return "fldl2e";
+ case 6:
+ return "fldl2t";
+ case 7:
+ return "fldpi";
+ }
+ abort ();
+}
+
+/* Return the CONST_DOUBLE representing the 80387 constant that is
+ loaded by the specified special instruction. The argument IDX
+ matches the return value from standard_80387_constant_p. */
+
+rtx
+standard_80387_constant_rtx (idx)
+ int idx;
+{
+ int i;
+
+ if (! ext_80387_constants_init)
+ init_ext_80387_constants ();
+
+ switch (idx)
+ {
+ case 3:
+ case 4:
+ case 5:
+ case 6:
+ case 7:
+ i = idx - 3;
+ break;
+
+ default:
+ abort ();
+ }
+
+ return CONST_DOUBLE_FROM_REAL_VALUE (ext_80387_constants_table[i], XFmode);
+}
+
/* Return 1 if X is FP constant we can load to SSE register w/o using memory.
*/
int
case 1: /* 0.0 */
*total = 1;
break;
- case 2: /* 1.0 */
+ default: /* Other constants */
*total = 2;
break;
- default:
+ case 0:
+ case -1:
/* Start with (MEM (SYMBOL_REF)), since that's where
it'll probably end up. Add a penalty for size. */
*total = (COSTS_N_INSNS (1)
return "fst%z0\t%y0";
case 2:
- switch (standard_80387_constant_p (operands[1]))
- {
- case 1:
- return "fldz";
- case 2:
- return "fld1";
- }
- abort();
+ return standard_80387_constant_opcode (operands[1]);
case 3:
case 4:
return "fst%z0\t%y0";
case 2:
- switch (standard_80387_constant_p (operands[1]))
- {
- case 1:
- return "fldz";
- case 2:
- return "fld1";
- }
- abort();
+ return standard_80387_constant_opcode (operands[1]);
case 3:
case 4:
return "fst%z0\t%y0";
case 2:
- switch (standard_80387_constant_p (operands[1]))
- {
- case 1:
- return "fldz";
- case 2:
- return "fld1";
- }
- abort();
+ return standard_80387_constant_opcode (operands[1]);
case 3:
case 4:
return "fst%z0\t%y0";
case 2:
- switch (standard_80387_constant_p (operands[1]))
- {
- case 1:
- return "fldz";
- case 2:
- return "fld1";
- }
- abort();
+ return standard_80387_constant_opcode (operands[1]);
case 3:
case 4:
return "fstp%z0\t%y0";
case 2:
- switch (standard_80387_constant_p (operands[1]))
- {
- case 1:
- return "fldz";
- case 2:
- return "fld1";
- }
- break;
+ return standard_80387_constant_opcode (operands[1]);
case 3: case 4:
return "#";
return "fstp%z0\t%y0";
case 2:
- switch (standard_80387_constant_p (operands[1]))
- {
- case 1:
- return "fldz";
- case 2:
- return "fld1";
- }
- break;
+ return standard_80387_constant_opcode (operands[1]);
case 3: case 4:
return "#";
return "fstp%z0\t%y0";
case 2:
- switch (standard_80387_constant_p (operands[1]))
- {
- case 1:
- return "fldz";
- case 2:
- return "fld1";
- }
- break;
+ return standard_80387_constant_opcode (operands[1]);
case 3: case 4:
return "#";
return "fstp%z0\t%y0";
case 2:
- switch (standard_80387_constant_p (operands[1]))
- {
- case 1:
- return "fldz";
- case 2:
- return "fld1";
- }
- break;
+ return standard_80387_constant_opcode (operands[1]);
case 3: case 4:
return "#";
projects / gcc.git / commitdiff