How do I tell the code generator to enable tail calls on the X86?
Since it is part of a library, I cannot pass a command line argument.
Of course I *can* call cl::ParseCommandLineOptions, but maybe there
should be something more straitforward than that?
Alexander Friedman wrote:
How do I tell the code generator to enable tail calls on the X86?
Since it is part of a library, I cannot pass a command line argument.
Here is a snippet from our code which might help you 
const char *args[] = { "-disable-pattern-isel", "false", 0 };
cl::ParseCommandLineOptions(2, args);
m.
Yup, something like this should work. Two comments though:
1. Morton, the pattern isel is now on by default for X86, and that option
doesn't exist. If you update to CVS you can remove that. Using
-enable-x86-fastcc should work with CVS though.
2. I haven't done much testing with the JIT and tail calls. I wouldn't be
suprised if there are minor issues that need to be fixed. I will try
to take a look and see what remains to be done over the next couple of
days.
-Chris
As I expected, there were issues. I fixed the following two problems:
1. The JIT didn't know where a call came from when it was a tail call (jmp
doesn't push a return address).
2. The JIT was clobbering EAX/EDX when lazily compiling a function, and
X86 fastcc wants to pass values in those registers.
I think things are working now, give it a spin and lemme know if you hit any problems.
-Chris
Chris Lattner wrote:
VC++ builds are working again.
However, llvm-test is broken. The configured makefile is bad:
# Path to the boxed-sim source code
@USE_BOXEDSIM@
BOXEDSIM_ROOT := @BOXEDSIM_ROOT@
Jeff Cohen wrote:
Boxedsim was nuked just before the 1.5 release. It was buggy and we
never got it working. Chances are your llvm-test tree is out of date?
Reid.
VC++ builds are working again.
However, llvm-test is broken. The configured makefile is bad:
Fixed. Thanks Jeff,
-Chris
Jeff Cohen wrote:
Chris Lattner wrote:
Yup, something like this should work. Two comments though:
2. I haven't done much testing with the JIT and tail calls. I wouldn't be
suprised if there are minor issues that need to be fixed. I will try
to take a look and see what remains to be done over the next couple of
days.As I expected, there were issues. I fixed the following two problems:
1. The JIT didn't know where a call came from when it was a tail call (jmp
doesn't push a return address).
2. The JIT was clobbering EAX/EDX when lazily compiling a function, and
X86 fastcc wants to pass values in those registers.I think things are working now, give it a spin and lemme know if you hit any problems.
-Chris
VC++ build is broken as a result of this change. I'll get it fixed soon.
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-Chris