[libc-commits] [libc] [libc][i386] setjmp/longjmp (PR #112437)

[James Y Knight via libc-commits]

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@@ -7,15 +7,34 @@
 //===----------------------------------------------------------------------===//
 
 #include "src/setjmp/longjmp.h"
+#include "include/llvm-libc-macros/offsetof-macro.h"
 #include "src/__support/common.h"
 #include "src/__support/macros/config.h"
 
-#if !defined(LIBC_TARGET_ARCH_IS_X86_64)
+#if !defined(LIBC_TARGET_ARCH_IS_X86)
 #error "Invalid file include"
 #endif
 
 namespace LIBC_NAMESPACE_DECL {
 
+#ifdef __i386__
+[[noreturn]]
+LLVM_LIBC_FUNCTION(void, longjmp, (jmp_buf buf, int val)) {
+  asm(R"(
----------------
jyknight wrote:

"m" constraint means that the operand is passed as an address, and emits the operand using syntax which specifies a memory load/store of that address (e.g. `(%rax)` vs `%rax`). It may either provide the address in a register, or with some more complex target-specific address expression (e.g. base+offset*scale on x86). But in any case, it has to use at least one register, unless the address is of a global with a load-time-constant address (not the case here), and your target supports arbitrary relocatable symbols in its memory access operands (which x86 does, but most other architectures don't).

https://github.com/llvm/llvm-project/pull/112437