Mercurial > projects > ldc
changeset 1410:cc2d8a7388c7
Count the sret register as well when keeping track of how many integer registers
are available for extern(C) functions on x86-64.
Interestingly, llvm-g++ seems to have a very similar bug: http://llvm.org/pr4242
(So this breaks ABI-compatibility with llvm-gcc for this corner case, but gains
it with gcc...)
To clarify, this is about code like this:
{{{
struct S { void*[3] data; }
struct T { void*[2] data; }
// The T should be passed in memory, and p in the last int register.
extern(C) S fail(int, int, int, int, T t, void* p) {
S s;
s.data[0] = t.data[0];
s.data[1] = t.data[1];
s.data[2] = p;
return s;
}
}}}
which should generate code functionally equivalent to this:
{{{
extern(C) S* succeed(S* s, int, int, int, int, T t, void* p) {
s.data[0] = t.data[0];
s.data[1] = t.data[1];
s.data[2] = p;
return s;
}
}}}
(with the same definitions for S and T)
author | Frits van Bommel <fvbommel wxs.nl> |
---|---|
date | Fri, 22 May 2009 13:17:06 +0200 |
parents | ecfec65d86cf |
children | e57859ca8f1e |
files | gen/abi-x86-64.cpp |
diffstat | 1 files changed, 8 insertions(+), 1 deletions(-) [+] |
line wrap: on
line diff
--- a/gen/abi-x86-64.cpp Fri May 22 10:18:04 2009 +0200 +++ b/gen/abi-x86-64.cpp Fri May 22 13:17:06 2009 +0200 @@ -562,7 +562,14 @@ return false; Classification cl = classify(rt); - return cl.isMemory; + if (cl.isMemory) { + assert(state().int_regs > 0 + && "No int registers available when determining sret-ness?"); + // An sret parameter takes an integer register. + state().int_regs--; + return true; + } + return false; } }