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use 64-bit memset on 64-bit platforms. Fixes #1546. Fixes #843.

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Actually, we don't "fix" #843 so much as close it: as with memmove,
we simply use an alignment of 1 with dynamically sized types.
This commit is contained in:
Niko Matsakis 2012-01-17 15:51:45 -08:00
parent 7bc2930cfa
commit 31b25d81eb
1 changed files with 12 additions and 22 deletions
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34
src/comp/middle/trans.rs
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@ -1944,24 +1944,6 @@ fn call_memmove(cx: @block_ctxt, dst: ValueRef, src: ValueRef,
ret rslt(cx, ret_val);
}
fn call_bzero(cx: @block_ctxt, dst: ValueRef, n_bytes: ValueRef,
align_bytes: ValueRef) -> result {
// FIXME: switch to the 64-bit variant when on such a platform.
let ccx = bcx_ccx(cx);
let i = ccx.intrinsics;
assert (i.contains_key("llvm.memset.p0i8.i32"));
let memset = i.get("llvm.memset.p0i8.i32");
let dst_ptr = PointerCast(cx, dst, T_ptr(T_i8()));
let size = IntCast(cx, n_bytes, T_i32());
let align =
if lib::llvm::llvm::LLVMIsConstant(align_bytes) == True {
IntCast(cx, align_bytes, T_i32())
} else { IntCast(cx, C_int(ccx, 0), T_i32()) };
let volatile = C_bool(false);
ret rslt(cx,
Call(cx, memset, [dst_ptr, C_u8(0u), size, align, volatile]));
}
fn memmove_ty(bcx: @block_ctxt, dst: ValueRef, src: ValueRef, t: ty::t) ->
@block_ctxt {
let ccx = bcx_ccx(bcx);
@ -3985,10 +3967,18 @@ fn zero_alloca(cx: @block_ctxt, llptr: ValueRef, t: ty::t)
let llty = type_of(ccx, sp, t);
Store(bcx, C_null(llty), llptr);
} else {
let llsz = size_of(bcx, t);
// FIXME passing in the align here is correct, but causes issue #843
// let llalign = align_of(llsz.bcx, t);
bcx = call_bzero(llsz.bcx, llptr, llsz.val, C_int(ccx, 0)).bcx;
let key = alt ccx.sess.targ_cfg.arch {
session::arch_x86. | session::arch_arm. { "llvm.memset.p0i8.i32" }
session::arch_x86_64. { "llvm.memset.p0i8.i64" }
};
let i = ccx.intrinsics;
let memset = i.get(key);
let dst_ptr = PointerCast(cx, llptr, T_ptr(T_i8()));
let size = size_of(cx, t);
bcx = size.bcx;
let align = C_i32(1i32); // cannot use computed value here.
let volatile = C_bool(false);
Call(cx, memset, [dst_ptr, C_u8(0u), size.val, align, volatile]);
}
ret bcx;
}