@@ -427,15 +427,31 @@ static inline void tcg_out_dat_imm(TCGContext *s,
(rn << 16) | (rd << 12) | im);
}
-static inline void tcg_out_movi32(TCGContext *s,
- int cond, int rd, uint32_t arg)
-{
- /* TODO: This is very suboptimal, we can easily have a constant
- * pool somewhere after all the instructions. */
- if ((int)arg < 0 && (int)arg >= -0x100) {
- tcg_out_dat_imm(s, cond, ARITH_MVN, rd, 0, (~arg) & 0xff);
- } else if (use_armv7_instructions) {
- /* use movw/movt */
+static void tcg_out_movi32(TCGContext *s, int cond, int rd, uint32_t arg)
+{
+ int rot, opc, rn;
+
+ /* For armv7, make sure not to use movw+movt when mov/mvn would do.
+ Speed things up by only checking when movt would be required.
+ Prior to armv7, have one go at fully rotated immediates before
+ doing the decomposition thing below. */
+ if (!use_armv7_instructions || (arg & 0xffff0000)) {
+ rot = encode_imm(arg);
+ if (rot >= 0) {
+ tcg_out_dat_imm(s, cond, ARITH_MOV, rd, 0,
+ rotl(arg, rot) | (rot << 7));
+ return;
+ }
+ rot = encode_imm(~arg);
+ if (rot >= 0) {
+ tcg_out_dat_imm(s, cond, ARITH_MVN, rd, 0,
+ rotl(~arg, rot) | (rot << 7));
+ return;
+ }
+ }
+
+ /* Use movw + movt. */
+ if (use_armv7_instructions) {
/* movw */
tcg_out32(s, (cond << 28) | 0x03000000 | (rd << 12)
| ((arg << 4) & 0x000f0000) | (arg & 0xfff));
@@ -444,22 +460,27 @@ static inline void tcg_out_movi32(TCGContext *s,
tcg_out32(s, (cond << 28) | 0x03400000 | (rd << 12)
| ((arg >> 12) & 0x000f0000) | ((arg >> 16) & 0xfff));
}
- } else {
- int opc = ARITH_MOV;
- int rn = 0;
-
- do {
- int i, rot;
-
- i = ctz32(arg) & ~1;
- rot = ((32 - i) << 7) & 0xf00;
- tcg_out_dat_imm(s, cond, opc, rd, rn, ((arg >> i) & 0xff) | rot);
- arg &= ~(0xff << i);
+ return;
+ }
- opc = ARITH_ORR;
- rn = rd;
- } while (arg);
+ /* TODO: This is very suboptimal, we can easily have a constant
+ pool somewhere after all the instructions. */
+ opc = ARITH_MOV;
+ rn = 0;
+ /* If we have lots of leading 1's, we can shorten the sequence by
+ beginning with mvn and then clearing higher bits with eor. */
+ if (clz32(~arg) > clz32(arg)) {
+ opc = ARITH_MVN, arg = ~arg;
}
+ do {
+ int i = ctz32(arg) & ~1;
+ rot = ((32 - i) << 7) & 0xf00;
+ tcg_out_dat_imm(s, cond, opc, rd, rn, ((arg >> i) & 0xff) | rot);
+ arg &= ~(0xff << i);
+
+ opc = ARITH_EOR;
+ rn = rd;
+ } while (arg);
}
static inline void tcg_out_dat_rI(TCGContext *s, int cond, int opc, TCGArg dst,
Try fully rotated arguments to mov and mvn before trying movt or full decomposition. Begin decomposition with mvn when it looks like it'll help. Examples include -: mov r9, #0x00000fa0 -: orr r9, r9, #0x000ee000 -: orr r9, r9, #0x0ff00000 -: orr r9, r9, #0xf0000000 +: mvn r9, #0x0000005f +: eor r9, r9, #0x00011000 Signed-off-by: Richard Henderson <rth@twiddle.net> --- tcg/arm/tcg-target.c | 67 ++++++++++++++++++++++++++++++++++------------------ 1 file changed, 44 insertions(+), 23 deletions(-)