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[Qemu-devel] [PATCH v5 6/7] tcg/arm: Try pc-relative addresses for movi
From: |
Richard Henderson |
Subject: |
[Qemu-devel] [PATCH v5 6/7] tcg/arm: Try pc-relative addresses for movi |
Date: |
Thu, 8 Jun 2017 22:37:18 -0700 |
Signed-off-by: Richard Henderson <address@hidden>
---
tcg/arm/tcg-target.inc.c | 44 +++++++++++++++++++++++++++++---------------
1 file changed, 29 insertions(+), 15 deletions(-)
diff --git a/tcg/arm/tcg-target.inc.c b/tcg/arm/tcg-target.inc.c
index fce382f..18708b1 100644
--- a/tcg/arm/tcg-target.inc.c
+++ b/tcg/arm/tcg-target.inc.c
@@ -418,25 +418,39 @@ static inline void tcg_out_dat_imm(TCGContext *s,
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);
+ int rot, opc, rn, diff;
+
+ /* Check a single MOV/MVN before anything else. */
+ 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;
+ }
+
+ /* Check for a pc-relative address. This will usually be the TB,
+ or within the TB, which is immediately before the code block. */
+ diff = arg - ((intptr_t)s->code_ptr + 8);
+ if (diff >= 0) {
+ rot = encode_imm(diff);
if (rot >= 0) {
- tcg_out_dat_imm(s, cond, ARITH_MOV, rd, 0,
- rotl(arg, rot) | (rot << 7));
+ tcg_out_dat_imm(s, cond, ARITH_ADD, rd, TCG_REG_PC,
+ rotl(diff, rot) | (rot << 7));
return;
- }
- rot = encode_imm(~arg);
+ }
+ } else {
+ rot = encode_imm(-diff);
if (rot >= 0) {
- tcg_out_dat_imm(s, cond, ARITH_MVN, rd, 0,
- rotl(~arg, rot) | (rot << 7));
+ tcg_out_dat_imm(s, cond, ARITH_SUB, rd, TCG_REG_PC,
+ rotl(-diff, rot) | (rot << 7));
return;
- }
+ }
}
/* Use movw + movt. */
--
2.9.4
- [Qemu-devel] [PATCH v5 0/7] tcg: allocate TB structs preceding translate, Richard Henderson, 2017/06/09
- [Qemu-devel] [PATCH v5 0/7] tcg: allocate TB structs preceding translate, Richard Henderson, 2017/06/09
- [Qemu-devel] [PATCH v5 0/7] tcg: allocate TB structs preceding translate, Richard Henderson, 2017/06/09
- [Qemu-devel] [PATCH v5 3/7] tcg/aarch64: Use ADR in tcg_out_movi, Richard Henderson, 2017/06/09
- [Qemu-devel] [PATCH v5 1/7] util: add cacheinfo, Richard Henderson, 2017/06/09
- [Qemu-devel] [PATCH v5 4/7] tcg/arm: Use indirect branch for goto_tb, Richard Henderson, 2017/06/09
- [Qemu-devel] [PATCH v5 2/7] tcg: allocate TB structs before the corresponding translated code, Richard Henderson, 2017/06/09
- [Qemu-devel] [PATCH v5 5/7] tcg/arm: Remove limit on code buffer size, Richard Henderson, 2017/06/09
- [Qemu-devel] [PATCH v5 6/7] tcg/arm: Try pc-relative addresses for movi,
Richard Henderson <=
- [Qemu-devel] [PATCH v5 7/7] tcg/arm: Use ldr (literal) for goto_tb, Richard Henderson, 2017/06/09
- Re: [Qemu-devel] [PATCH v5 0/7] tcg: allocate TB structs preceding translate, no-reply, 2017/06/09
- Re: [Qemu-devel] [PATCH v5 0/7] tcg: allocate TB structs preceding translate, Emilio G. Cota, 2017/06/09