merge: llvm auto-build (opt-in on x86-64), mode stamp

1 files changed, 1 insertions, 1 deletions

diff --git a/README.md b/README.md
index 75d01fb..73f2bc4 100644
--- a/README.md
+++ b/README.md
@@ -72,7 +72,7 @@ windows needs clang or gcc and powershell for the tests. the batch file is the s
 
 ### native backends
 
-on arm64, `src/core/core.c` uses its arm64 jit by default, and on x86-64 linux its x86-64 jit. other hosts use the interpreter. `-DZYINTERP` forces interpretation (`make build/bin/zyi` builds that core beside `zy`); `-DZYLLVM` enables the llvm backend when its headers and libraries are available. direct builds from the root are:
+on arm64, `src/core/core.c` uses its arm64 jit by default, and on x86-64 linux its x86-64 jit. other hosts use the interpreter. `-DZYINTERP` forces interpretation (`make build/bin/zyi` builds that core beside `zy`); `-DZYLLVM` enables the llvm backend when its headers and libraries are available. on x86_64 hosts (`uname -m`) `make` keeps the x86-64 jit in `zy` and adds the llvm backend only with `make LLVM=1`, since `-DZYLLVM` replaces that jit; on other hosts `make` adds it whenever it finds a usable llvm, and `make NOLLVM=1` leaves it out. the llvm is `LLVM_CONFIG` if given, else `llvm-config`, else `llvm-config-19` on `PATH`, and it counts only when `llvm-c/Core.h` exists, `--libs` is not empty and a tiny test program links; otherwise the build prints a one-line note and goes on without it. the chosen mode is kept in `build/llvm.mode`, so switching rebuilds `zy` without `make clean`. direct builds from the root are:
 
 ```sh
 make genome