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[Qemu-devel] [PATCH v4 18/18] tcg-arm: Tidy exit_tb
From: |
Richard Henderson |
Subject: |
[Qemu-devel] [PATCH v4 18/18] tcg-arm: Tidy exit_tb |
Date: |
Sat, 30 Mar 2013 13:43:27 -0700 |
Use tcg_out_movi32 when it's profitable, which is always for v7.
Simplify the logic around tcg_out_goto, now that we're sure that
it won't generate a multi-insn branch.
Signed-off-by: Richard Henderson <address@hidden>
---
tcg/arm/tcg-target.c | 19 +++++++++----------
1 file changed, 9 insertions(+), 10 deletions(-)
diff --git a/tcg/arm/tcg-target.c b/tcg/arm/tcg-target.c
index 844f1cf..077f0ae 100644
--- a/tcg/arm/tcg-target.c
+++ b/tcg/arm/tcg-target.c
@@ -1604,17 +1604,16 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode
opc,
switch (opc) {
case INDEX_op_exit_tb:
- {
- uint8_t *ld_ptr = s->code_ptr;
- if (args[0] >> 8)
- tcg_out_ld32_12(s, COND_AL, TCG_REG_R0, TCG_REG_PC, 0);
- else
- tcg_out_dat_imm(s, COND_AL, ARITH_MOV, TCG_REG_R0, 0, args[0]);
+ if (use_armv7_instructions || check_fit_imm(args[0])) {
+ tcg_out_movi32(s, COND_AL, TCG_REG_R0, args[0]);
tcg_out_goto(s, COND_AL, (tcg_target_ulong) tb_ret_addr);
- if (args[0] >> 8) {
- *ld_ptr = (uint8_t) (s->code_ptr - ld_ptr) - 8;
- tcg_out32(s, args[0]);
- }
+ } else {
+ /* Lacking a real constant pool, use a pc-relative load. Since
+ tcg_out_goto will always emit 1 insn, we know without further
+ ado that 0 plus the standard 8 bias is right. */
+ tcg_out_ld32_12(s, COND_AL, TCG_REG_R0, TCG_REG_PC, 0);
+ tcg_out_goto(s, COND_AL, (tcg_target_ulong) tb_ret_addr);
+ tcg_out32(s, args[0]);
}
break;
case INDEX_op_goto_tb:
--
1.8.1.4
- [Qemu-devel] [PATCH v4 07/18] tcg-arm: Improve constant generation, (continued)
- [Qemu-devel] [PATCH v4 07/18] tcg-arm: Improve constant generation, Richard Henderson, 2013/03/30
- [Qemu-devel] [PATCH v4 08/18] tcg-arm: Implement deposit for armv7, Richard Henderson, 2013/03/30
- [Qemu-devel] [PATCH v4 09/18] tcg-arm: Implement division instructions, Richard Henderson, 2013/03/30
- [Qemu-devel] [PATCH v4 10/18] tcg-arm: Use TCG_REG_TMP name for the tcg temporary, Richard Henderson, 2013/03/30
- [Qemu-devel] [PATCH v4 11/18] tcg-arm: Use R12 for the tcg temporary, Richard Henderson, 2013/03/30
- [Qemu-devel] [PATCH v4 12/18] tcg-arm: Cleanup multiply subroutines, Richard Henderson, 2013/03/30
- [Qemu-devel] [PATCH v4 13/18] tcg-arm: Cleanup most primitive load store subroutines, Richard Henderson, 2013/03/30
- [Qemu-devel] [PATCH v4 14/18] tcg-arm: Split out tcg_out_tlb_read, Richard Henderson, 2013/03/30
- [Qemu-devel] [PATCH v4 15/18] tcg-arm: Improve scheduling of tcg_out_tlb_read, Richard Henderson, 2013/03/30
- [Qemu-devel] [PATCH v4 16/18] tcg-arm: Use movi32 + blx for calls on v7, Richard Henderson, 2013/03/30
- [Qemu-devel] [PATCH v4 18/18] tcg-arm: Tidy exit_tb,
Richard Henderson <=
- [Qemu-devel] [PATCH v4 17/18] tcg-arm: Convert to CONFIG_QEMU_LDST_OPTIMIZATION, Richard Henderson, 2013/03/30