From 8a33034d82314e2a5a8f39f9348e93135f94807d Mon Sep 17 00:00:00 2001 From: Diego Russo Date: Wed, 19 Mar 2025 19:19:21 +0000 Subject: [PATCH] GH-130956: Only emit AArch64 trampolines for long jumps (GH-131041) --- .../2025-03-10-12-05-45.gh-issue-130956.f823Ih.rst | 1 + Python/jit.c | 12 +++++++++++- 2 files changed, 12 insertions(+), 1 deletion(-) create mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2025-03-10-12-05-45.gh-issue-130956.f823Ih.rst diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-03-10-12-05-45.gh-issue-130956.f823Ih.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-03-10-12-05-45.gh-issue-130956.f823Ih.rst new file mode 100644 index 00000000000..daf9c8ea09f --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-03-10-12-05-45.gh-issue-130956.f823Ih.rst @@ -0,0 +1 @@ +Optimize the AArch64 code generation for the JIT. Patch by Diego Russo diff --git a/Python/jit.c b/Python/jit.c index 092b873bc73..95b5a1b52b8 100644 --- a/Python/jit.c +++ b/Python/jit.c @@ -430,6 +430,17 @@ void patch_aarch64_trampoline(unsigned char *location, int ordinal, jit_state *s void patch_aarch64_trampoline(unsigned char *location, int ordinal, jit_state *state) { + + uint64_t value = (uintptr_t)symbols_map[ordinal]; + int64_t range = value - (uintptr_t)location; + + // If we are in range of 28 signed bits, we patch the instruction with + // the address of the symbol. + if (range >= -(1 << 27) && range < (1 << 27)) { + patch_aarch64_26r(location, (uintptr_t)value); + return; + } + // Masking is done modulo 32 as the mask is stored as an array of uint32_t const uint32_t symbol_mask = 1 << (ordinal % 32); const uint32_t trampoline_mask = state->trampolines.mask[ordinal / 32]; @@ -445,7 +456,6 @@ patch_aarch64_trampoline(unsigned char *location, int ordinal, jit_state *state) uint32_t *p = (uint32_t*)(state->trampolines.mem + index * TRAMPOLINE_SIZE); assert((size_t)(index + 1) * TRAMPOLINE_SIZE <= state->trampolines.size); - uint64_t value = (uintptr_t)symbols_map[ordinal]; /* Generate the trampoline 0: 58000048 ldr x8, 8