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[PATCH v6 09/26] tcg/tci: Improve tcg_target_call_clobber_regs
From: |
Richard Henderson |
Subject: |
[PATCH v6 09/26] tcg/tci: Improve tcg_target_call_clobber_regs |
Date: |
Sun, 2 May 2021 16:57:10 -0700 |
The current setting is much too pessimistic. Indicating only
the one or two registers that are actually assigned after a
call should avoid unnecessary movement between the register
array and the stack array.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
tcg/tci/tcg-target.c.inc | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/tcg/tci/tcg-target.c.inc b/tcg/tci/tcg-target.c.inc
index ee6cdfec71..fb7c927fdf 100644
--- a/tcg/tci/tcg-target.c.inc
+++ b/tcg/tci/tcg-target.c.inc
@@ -812,8 +812,14 @@ static void tcg_target_init(TCGContext *s)
tcg_target_available_regs[TCG_TYPE_I32] = BIT(TCG_TARGET_NB_REGS) - 1;
/* Registers available for 64 bit operations. */
tcg_target_available_regs[TCG_TYPE_I64] = BIT(TCG_TARGET_NB_REGS) - 1;
- /* TODO: Which registers should be set here? */
- tcg_target_call_clobber_regs = BIT(TCG_TARGET_NB_REGS) - 1;
+ /*
+ * The interpreter "registers" are in the local stack frame and
+ * cannot be clobbered by the called helper functions. However,
+ * the interpreter assumes a 64-bit return value and assigns to
+ * the return value registers.
+ */
+ tcg_target_call_clobber_regs =
+ MAKE_64BIT_MASK(TCG_REG_R0, 64 / TCG_TARGET_REG_BITS);
s->reserved_regs = 0;
tcg_regset_set_reg(s->reserved_regs, TCG_REG_CALL_STACK);
--
2.25.1
- Re: [PATCH v6 07/26] tcg: Add tcg_call_func, (continued)
[PATCH v6 08/26] tcg: Build ffi data structures for helpers, Richard Henderson, 2021/05/02
[PATCH v6 10/26] tcg/tci: Move call-return regs to end of tcg_target_reg_alloc_order, Richard Henderson, 2021/05/02
[PATCH v6 13/26] tcg/tci: Emit setcond before brcond, Richard Henderson, 2021/05/02
[PATCH v6 11/26] tcg/tci: Use ffi for calls, Richard Henderson, 2021/05/02
[PATCH v6 14/26] tcg/tci: Remove tci_write_reg, Richard Henderson, 2021/05/02
[PATCH v6 09/26] tcg/tci: Improve tcg_target_call_clobber_regs,
Richard Henderson <=
[PATCH v6 12/26] tcg/tci: Reserve r13 for a temporary, Richard Henderson, 2021/05/02
[PATCH v6 18/26] tcg/tci: Implement andc, orc, eqv, nand, nor, Richard Henderson, 2021/05/02
[PATCH v6 17/26] tcg/tci: Implement movcond, Richard Henderson, 2021/05/02
[PATCH v6 19/26] tcg/tci: Implement extract, sextract, Richard Henderson, 2021/05/02
[PATCH v6 15/26] tcg/tci: Change encoding to uint32_t units, Richard Henderson, 2021/05/02
[PATCH v6 22/26] tcg/tci: Implement add2, sub2, Richard Henderson, 2021/05/02
[PATCH v6 16/26] tcg/tci: Implement goto_ptr, Richard Henderson, 2021/05/02