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tcg/aarch64: Build vector immediates with two insns

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Use MOVI+ORR or MVNI+BIC in order to build some vector constants,
as opposed to dropping them to the constant pool.  This includes
all 16-bit constants and a similar set of 32-bit constants.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2019-05-14 12:47:02 -07:00
parent 7e308e003e
commit 02f3a5b474
1 changed files with 47 additions and 0 deletions
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47
tcg/aarch64/tcg-target.inc.c
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@ -273,6 +273,26 @@ static bool is_fimm64(uint64_t v64, int *cmode, int *imm8)
return false;
}
/*
* Return non-zero if v32 can be formed by MOVI+ORR.
* Place the parameters for MOVI in (cmode, imm8).
* Return the cmode for ORR; the imm8 can be had via extraction from v32.
*/
static int is_shimm32_pair(uint32_t v32, int *cmode, int *imm8)
{
int i;
for (i = 6; i > 0; i -= 2) {
/* Mask out one byte we can add with ORR. */
uint32_t tmp = v32 & ~(0xffu << (i * 4));
if (is_shimm32(tmp, cmode, imm8) ||
is_soimm32(tmp, cmode, imm8)) {
break;
}
}
return i;
}
static int tcg_target_const_match(tcg_target_long val, TCGType type,
const TCGArgConstraint *arg_ct)
{
@ -495,6 +515,8 @@ typedef enum {
/* AdvSIMD modified immediate */
I3606_MOVI = 0x0f000400,
I3606_MVNI = 0x2f000400,
I3606_BIC = 0x2f001400,
I3606_ORR = 0x0f001400,
/* AdvSIMD shift by immediate */
I3614_SSHR = 0x0f000400,
@ -843,6 +865,14 @@ static void tcg_out_dupi_vec(TCGContext *s, TCGType type,
tcg_out_insn(s, 3606, MVNI, q, rd, 0, cmode, imm8);
return;
}
/*
* Otherwise, all remaining constants can be loaded in two insns:
* rd = v16 & 0xff, rd |= v16 & 0xff00.
*/
tcg_out_insn(s, 3606, MOVI, q, rd, 0, 0x8, v16 & 0xff);
tcg_out_insn(s, 3606, ORR, q, rd, 0, 0xa, v16 >> 8);
return;
} else if (v64 == dup_const(MO_32, v64)) {
uint32_t v32 = v64;
uint32_t n32 = ~v32;
@ -858,6 +888,23 @@ static void tcg_out_dupi_vec(TCGContext *s, TCGType type,
tcg_out_insn(s, 3606, MVNI, q, rd, 0, cmode, imm8);
return;
}
/*
* Restrict the set of constants to those we can load with
* two instructions. Others we load from the pool.
*/
i = is_shimm32_pair(v32, &cmode, &imm8);
if (i) {
tcg_out_insn(s, 3606, MOVI, q, rd, 0, cmode, imm8);
tcg_out_insn(s, 3606, ORR, q, rd, 0, i, extract32(v32, i * 4, 8));
return;
}
i = is_shimm32_pair(n32, &cmode, &imm8);
if (i) {
tcg_out_insn(s, 3606, MVNI, q, rd, 0, cmode, imm8);
tcg_out_insn(s, 3606, BIC, q, rd, 0, i, extract32(n32, i * 4, 8));
return;
}
} else if (is_fimm64(v64, &cmode, &imm8)) {
tcg_out_insn(s, 3606, MOVI, q, rd, 1, cmode, imm8);
return;