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[PATCH v7 09/27] tcg/tci: Improve tcg_target_call_clobber_regs
From: |
Richard Henderson |
Subject: |
[PATCH v7 09/27] tcg/tci: Improve tcg_target_call_clobber_regs |
Date: |
Tue, 1 Jun 2021 08:00:48 -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.
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
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
- [PATCH v7 00/27] TCI fixes and cleanups, Richard Henderson, 2021/06/01
- [PATCH v7 02/27] tcg: Add tcg_call_flags, Richard Henderson, 2021/06/01
- [PATCH v7 03/27] accel/tcg/plugin-gen: Drop inline markers, Richard Henderson, 2021/06/01
- [PATCH v7 01/27] tcg: Combine dh_is_64bit and dh_is_signed to dh_typecode, Richard Henderson, 2021/06/01
- [PATCH v7 04/27] plugins: Drop tcg_flags from struct qemu_plugin_dyn_cb, Richard Henderson, 2021/06/01
- [PATCH v7 07/27] tcg: Add tcg_call_func, Richard Henderson, 2021/06/01
- [PATCH v7 05/27] accel/tcg: Add tcg call flags to plugins helpers, Richard Henderson, 2021/06/01
- [PATCH v7 06/27] tcg: Store the TCGHelperInfo in the TCGOp for call, Richard Henderson, 2021/06/01
- [PATCH v7 09/27] tcg/tci: Improve tcg_target_call_clobber_regs,
Richard Henderson <=
- [PATCH v7 10/27] tcg/tci: Move call-return regs to end of tcg_target_reg_alloc_order, Richard Henderson, 2021/06/01
- [PATCH v7 13/27] tcg/tci: Emit setcond before brcond, Richard Henderson, 2021/06/01
- [PATCH v7 15/27] tcg/tci: Change encoding to uint32_t units, Richard Henderson, 2021/06/01
- [PATCH v7 08/27] tcg: Build ffi data structures for helpers, Richard Henderson, 2021/06/01