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[PULL 09/33] tcg/tci: Improve tcg_target_call_clobber_regs
From: |
Richard Henderson |
Subject: |
[PULL 09/33] tcg/tci: Improve tcg_target_call_clobber_regs |
Date: |
Sat, 19 Jun 2021 11:14:28 -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>
Reviewed-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 823ecd5d35..8f3f9ef7d3 100644
--- a/tcg/tci/tcg-target.c.inc
+++ b/tcg/tci/tcg-target.c.inc
@@ -810,8 +810,14 @@ 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
- [PULL 00/33] tcg patch queue, Richard Henderson, 2021/06/19
- [PULL 01/33] tcg: Combine dh_is_64bit and dh_is_signed to dh_typecode, Richard Henderson, 2021/06/19
- [PULL 03/33] accel/tcg/plugin-gen: Drop inline markers, Richard Henderson, 2021/06/19
- [PULL 04/33] plugins: Drop tcg_flags from struct qemu_plugin_dyn_cb, Richard Henderson, 2021/06/19
- [PULL 06/33] tcg: Store the TCGHelperInfo in the TCGOp for call, Richard Henderson, 2021/06/19
- [PULL 05/33] accel/tcg: Add tcg call flags to plugins helpers, Richard Henderson, 2021/06/19
- [PULL 07/33] tcg: Add tcg_call_func, Richard Henderson, 2021/06/19
- [PULL 08/33] tcg: Build ffi data structures for helpers, Richard Henderson, 2021/06/19
- [PULL 09/33] tcg/tci: Improve tcg_target_call_clobber_regs,
Richard Henderson <=
- [PULL 02/33] tcg: Add tcg_call_flags, Richard Henderson, 2021/06/19
- [PULL 10/33] tcg/tci: Move call-return regs to end of tcg_target_reg_alloc_order, Richard Henderson, 2021/06/19
- [PULL 11/33] tcg/tci: Use ffi for calls, Richard Henderson, 2021/06/19
- [PULL 18/33] tcg/tci: Implement andc, orc, eqv, nand, nor, Richard Henderson, 2021/06/19
- [PULL 12/33] tcg/tci: Reserve r13 for a temporary, Richard Henderson, 2021/06/19
- [PULL 30/33] tcg: Allocate sufficient storage in temp_allocate_frame, Richard Henderson, 2021/06/19
- [PULL 26/33] tcg/tci: Use {set,clear}_helper_retaddr, Richard Henderson, 2021/06/19
- [PULL 25/33] tcg/tci: Remove the qemu_ld/st_type macros, Richard Henderson, 2021/06/19
- [PULL 31/33] tcg: Restart when exhausting the stack frame, Richard Henderson, 2021/06/19
- [PULL 14/33] tcg/tci: Remove tci_write_reg, Richard Henderson, 2021/06/19