On 3/8/25 01:28, Richard Henderson wrote:
This array is within CPUNegativeOffsetState, which means the
last element of the array has an offset from env with the
smallest magnitude. This can be encoded into fewer bits
when generating TCG fast path memory references.
When we changed the NB_MMU_MODES to be a global constant,
rather than a per-target value, we pessimized the code
generated for targets which use only a few mmu indexes.
By inverting the array index, we counteract that.
Reviewed-by: Pierrick Bouvier <pierrick.bouv...@linaro.org>
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
include/hw/core/cpu.h | 11 ++++++++++-
tcg/tcg.c | 3 ++-
2 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index bd835b07d5..23eb849a9b 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -594,9 +594,18 @@ static inline CPUArchState *cpu_env(CPUState *cpu)
}
#ifdef CONFIG_TCG
+/*
+ * Invert the index order of the CPUTLBDescFast array so that lower
+ * mmu_idx have offsets from env with smaller magnitude.
+ */
+static inline int mmuidx_to_fast_index(int mmu_idx)
(unsigned?)
+{
+ return NB_MMU_MODES - 1 - mmu_idx;
+}
Reviewed-by: Philippe Mathieu-Daudé <phi...@linaro.org>
