diff options
Diffstat (limited to 'llvm/lib/Target')
| -rw-r--r-- | llvm/lib/Target/X86/X86JITInfo.cpp | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/llvm/lib/Target/X86/X86JITInfo.cpp b/llvm/lib/Target/X86/X86JITInfo.cpp index f7d1118d700..7b3a0703277 100644 --- a/llvm/lib/Target/X86/X86JITInfo.cpp +++ b/llvm/lib/Target/X86/X86JITInfo.cpp @@ -352,7 +352,8 @@ X86CompilationCallback2(intptr_t *StackPtr, intptr_t RetAddr) { // Rewrite the call target... so that we don't end up here every time we // execute the call. #if defined (X86_64_JIT) - *(intptr_t *)(RetAddr - 0xa) = NewVal; + if (!isStub) + *(intptr_t *)(RetAddr - 0xa) = NewVal; #else *(intptr_t *)RetAddr = (intptr_t)(NewVal-RetAddr-4); #endif @@ -363,7 +364,18 @@ X86CompilationCallback2(intptr_t *StackPtr, intptr_t RetAddr) { // when the requested function finally gets called. This also makes the // 0xCD byte (interrupt) dead, so the marker doesn't effect anything. #if defined (X86_64_JIT) - ((unsigned char*)RetAddr)[0] = (2 | (4 << 3) | (3 << 6)); + // If the target address is within 32-bit range of the stub, use a + // PC-relative branch instead of loading the actual address. (This is + // considerably shorter than the 64-bit immediate load already there.) + // We assume here intptr_t is 64 bits. + intptr_t diff = NewVal-RetAddr+7; + if (diff >= -2147483648LL && diff <= 2147483647LL) { + *(unsigned char*)(RetAddr-0xc) = 0xE9; + *(intptr_t *)(RetAddr-0xb) = diff & 0xffffffff; + } else { + *(intptr_t *)(RetAddr - 0xa) = NewVal; + ((unsigned char*)RetAddr)[0] = (2 | (4 << 3) | (3 << 6)); + } #else ((unsigned char*)RetAddr)[-1] = 0xE9; #endif |
