From c0c4a46db805208f56509f85123d31e8255234ca Mon Sep 17 00:00:00 2001
From: rth <rth@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Sun, 12 May 2002 17:09:24 +0000
Subject: * expr.c (compress_float_constant): New.
(emit_move_insn): Use it. (float_extend_from_mem): New.
(init_expr_once): Initialize it. * real.c (exact_real_truncate): New.
* config/i386/i386.h (CONST_COSTS): Assume CONST_DOUBLE gets
dropped into memory; penalize for size.
(RTX_COSTS): FLOAT_EXTEND is free.
* config/i386/i386.md (extendsfdf2, extendsfxf2, extendsftf2,
extenddfxf2, extenddftf2): Accept constants and drop them to memory.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@53401 138bc75d-0d04-0410-961f-82ee72b054a4
---
gcc/expr.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 96 insertions(+), 3 deletions(-)
(limited to 'gcc/expr.c')
diff --git a/gcc/expr.c b/gcc/expr.c
index 84443e014e6..1a8d0518323 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -134,6 +134,7 @@ static void store_by_pieces_1 PARAMS ((struct store_by_pieces *,
static void store_by_pieces_2 PARAMS ((rtx (*) (rtx, ...),
enum machine_mode,
struct store_by_pieces *));
+static rtx compress_float_constant PARAMS ((rtx, rtx));
static rtx get_subtarget PARAMS ((rtx));
static int is_zeros_p PARAMS ((tree));
static int mostly_zeros_p PARAMS ((tree));
@@ -167,6 +168,10 @@ static void do_tablejump PARAMS ((rtx, enum machine_mode, rtx, rtx, rtx));
static char direct_load[NUM_MACHINE_MODES];
static char direct_store[NUM_MACHINE_MODES];
+/* Record for each mode whether we can float-extend from memory. */
+
+static bool float_extend_from_mem[NUM_MACHINE_MODES][NUM_MACHINE_MODES];
+
/* If a memory-to-memory move would take MOVE_RATIO or more simple
move-instruction sequences, we will do a movstr or libcall instead. */
@@ -265,6 +270,28 @@ init_expr_once ()
}
}
+ mem = gen_rtx_MEM (VOIDmode, gen_rtx_raw_REG (Pmode, 10000));
+
+ for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT); mode != VOIDmode;
+ mode = GET_MODE_WIDER_MODE (mode))
+ {
+ enum machine_mode srcmode;
+ for (srcmode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT); srcmode != mode;
+ srcmode = GET_MODE_WIDER_MODE (srcmode))
+ {
+ enum insn_code ic;
+
+ ic = can_extend_p (mode, srcmode, 0);
+ if (ic == CODE_FOR_nothing)
+ continue;
+
+ PUT_MODE (mem, srcmode);
+
+ if ((*insn_data[ic].operand[1].predicate) (mem, srcmode))
+ float_extend_from_mem[mode][srcmode] = true;
+ }
+ }
+
end_sequence ();
}
@@ -2771,10 +2798,18 @@ emit_move_insn (x, y)
/* Never force constant_p_rtx to memory. */
if (GET_CODE (y) == CONSTANT_P_RTX)
;
- else if (CONSTANT_P (y) && ! LEGITIMATE_CONSTANT_P (y))
+ else if (CONSTANT_P (y))
{
- y_cst = y;
- y = force_const_mem (mode, y);
+ if (optimize
+ && FLOAT_MODE_P (GET_MODE (x))
+ && (last_insn = compress_float_constant (x, y)))
+ return last_insn;
+
+ if (!LEGITIMATE_CONSTANT_P (y))
+ {
+ y_cst = y;
+ y = force_const_mem (mode, y);
+ }
}
/* If X or Y are memory references, verify that their addresses are valid
@@ -3100,6 +3135,64 @@ emit_move_insn_1 (x, y)
else
abort ();
}
+
+/* If Y is representable exactly in a narrower mode, and the target can
+ perform the extension directly from constant or memory, then emit the
+ move as an extension. */
+
+static rtx
+compress_float_constant (x, y)
+ rtx x, y;
+{
+ enum machine_mode dstmode = GET_MODE (x);
+ enum machine_mode orig_srcmode = GET_MODE (y);
+ enum machine_mode srcmode;
+ REAL_VALUE_TYPE r;
+
+ REAL_VALUE_FROM_CONST_DOUBLE (r, y);
+
+ for (srcmode = GET_CLASS_NARROWEST_MODE (GET_MODE_CLASS (orig_srcmode));
+ srcmode != orig_srcmode;
+ srcmode = GET_MODE_WIDER_MODE (srcmode))
+ {
+ enum insn_code ic;
+ rtx trunc_y, last_insn;
+
+ /* Skip if the target can't extend this way. */
+ ic = can_extend_p (dstmode, srcmode, 0);
+ if (ic == CODE_FOR_nothing)
+ continue;
+
+ /* Skip if the narrowed value isn't exact. */
+ if (! exact_real_truncate (srcmode, &r))
+ continue;
+
+ trunc_y = CONST_DOUBLE_FROM_REAL_VALUE (r, srcmode);
+
+ if (LEGITIMATE_CONSTANT_P (trunc_y))
+ {
+ /* Skip if the target needs extra instructions to perform
+ the extension. */
+ if (! (*insn_data[ic].operand[1].predicate) (trunc_y, srcmode))
+ continue;
+ }
+ else if (float_extend_from_mem[dstmode][srcmode])
+ trunc_y = validize_mem (force_const_mem (srcmode, trunc_y));
+ else
+ continue;
+
+ emit_unop_insn (ic, x, trunc_y, UNKNOWN);
+ last_insn = get_last_insn ();
+
+ if (GET_CODE (x) == REG)
+ REG_NOTES (last_insn)
+ = gen_rtx_EXPR_LIST (REG_EQUAL, y, REG_NOTES (last_insn));
+
+ return last_insn;
+ }
+
+ return NULL_RTX;
+}
/* Pushing data onto the stack. */
--
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