Skip to content

possible fix for byval issue #1296

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
regehr wants to merge 1 commit into from
+36 −3
Closed

possible fix for byval issue #1296

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
16 changes: 13 additions & 3 deletions ir/pointer.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -852,9 +852,19 @@ expr Pointer::fninputRefined(const Pointer &other, set<expr> &undef,
auto [p1l, d1] = toLogicalLocal();
auto [p2l, d2] = other.toLogicalLocal();

// TODO: check block value for byval_bytes
if (!byval_bytes.isZero())
return true;
if (!byval_bytes.isZero()) {
uint64_t bytes;
if (!byval_bytes.isUInt(bytes))
return false;
Copy link
Copy Markdown
Member

@nunoplopes nunoplopes Mar 17, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

byval bytes can be a variable. The code needs to support this case or leave the TODO there and return true to avoid false positives. In general this requires doing a memcmp using a lambda (which is not implemented in memory.cpp yet).


expr byval_refined = true;
for (uint64_t off = 0; off < bytes; ++off) {
auto src_byte = m.raw_load(*this + off, undef);
auto tgt_byte = other.m.raw_load(other + off, undef);
byval_refined &= src_byte.refined(tgt_byte);
}
return byval_refined;
}

expr local = d2 && (p2l.isLocal() || p2l.isByval()) &&
at_least_same_offseting(p1l, p2l, false);
Expand Down
23 changes: 23 additions & 0 deletions tests/alive-tv/calls/byval-copy-mismatch.srctgt.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,23 @@
; ERROR: Source is more defined than target

declare i32 @g(ptr byval(i32))

define i32 @src() {
entry:
%p = alloca i32, align 4
%q = alloca i32, align 4
store i32 1, ptr %p, align 4
store i32 2, ptr %q, align 4
%r = call i32 @g(ptr byval(i32) %p)
ret i32 %r
}

define i32 @tgt() {
entry:
%p = alloca i32, align 4
%q = alloca i32, align 4
store i32 1, ptr %p, align 4
store i32 2, ptr %q, align 4
%r = call i32 @g(ptr byval(i32) %q)
ret i32 %r
}
Loading