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[Qemu-devel] [PULL for-2.1 24/25] tcg-aarch64: Prefer unsigned offsets b
From: |
Richard Henderson |
Subject: |
[Qemu-devel] [PULL for-2.1 24/25] tcg-aarch64: Prefer unsigned offsets before signed offsets for ldst |
Date: |
Wed, 16 Apr 2014 09:18:07 -0700 |
The assembler seems to prefer them, perhaps we should too.
Reviewed-by: Claudio Fontana <address@hidden>
Signed-off-by: Richard Henderson <address@hidden>
---
tcg/aarch64/tcg-target.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/tcg/aarch64/tcg-target.c b/tcg/aarch64/tcg-target.c
index 3235824..7ff4be7 100644
--- a/tcg/aarch64/tcg-target.c
+++ b/tcg/aarch64/tcg-target.c
@@ -669,11 +669,6 @@ static void tcg_out_ldst(TCGContext *s, AArch64Insn insn,
{
TCGMemOp size = (uint32_t)insn >> 30;
- if (offset >= -256 && offset < 256) {
- tcg_out_insn_3312(s, insn, rd, rn, offset);
- return;
- }
-
/* If the offset is naturally aligned and in range, then we can
use the scaled uimm12 encoding */
if (offset >= 0 && !(offset & ((1 << size) - 1))) {
@@ -684,6 +679,12 @@ static void tcg_out_ldst(TCGContext *s, AArch64Insn insn,
}
}
+ /* Small signed offsets can use the unscaled encoding. */
+ if (offset >= -256 && offset < 256) {
+ tcg_out_insn_3312(s, insn, rd, rn, offset);
+ return;
+ }
+
/* Worst-case scenario, move offset to temp register, use reg offset. */
tcg_out_movi(s, TCG_TYPE_I64, TCG_REG_TMP, offset);
tcg_out_ldst_r(s, insn, rd, rn, TCG_REG_TMP);
--
1.9.0
- [Qemu-devel] [PULL for-2.1 15/25] tcg-aarch64: Use tcg_out_call for qemu_ld/st, (continued)
- [Qemu-devel] [PULL for-2.1 15/25] tcg-aarch64: Use tcg_out_call for qemu_ld/st, Richard Henderson, 2014/04/16
- [Qemu-devel] [PULL for-2.1 16/25] tcg-aarch64: Use ADR to pass the return address to the ld/st helpers, Richard Henderson, 2014/04/16
- [Qemu-devel] [PULL for-2.1 17/25] tcg-aarch64: Use TCGMemOp in qemu_ld/st, Richard Henderson, 2014/04/16
- [Qemu-devel] [PULL for-2.1 18/25] tcg-aarch64: Pass qemu_ld/st arguments directly, Richard Henderson, 2014/04/16
- [Qemu-devel] [PULL for-2.1 13/25] tcg-aarch64: Implement tcg_register_jit, Richard Henderson, 2014/04/16
- [Qemu-devel] [PULL for-2.1 20/25] tcg-aarch64: Support stores of zero, Richard Henderson, 2014/04/16
- [Qemu-devel] [PULL for-2.1 19/25] tcg-aarch64: Implement TCG_TARGET_HAS_new_ldst, Richard Henderson, 2014/04/16
- [Qemu-devel] [PULL for-2.1 21/25] tcg-aarch64: Introduce tcg_out_insn_3507, Richard Henderson, 2014/04/16
- [Qemu-devel] [PULL for-2.1 22/25] tcg-aarch64: Merge aarch64_ldst_get_data/type into tcg_out_op, Richard Henderson, 2014/04/16
- [Qemu-devel] [PULL for-2.1 23/25] tcg-aarch64: Introduce tcg_out_insn_3312, _3310, _3313, Richard Henderson, 2014/04/16
- [Qemu-devel] [PULL for-2.1 24/25] tcg-aarch64: Prefer unsigned offsets before signed offsets for ldst,
Richard Henderson <=
- [Qemu-devel] [PULL for-2.1 25/25] tcg-aarch64: Use tcg_out_mov in preference to tcg_out_movr, Richard Henderson, 2014/04/16
- Re: [Qemu-devel] [PULL for-2.1 00/25] tcg-aarch64 improvements, Peter Maydell, 2014/04/17