Just as as llvm IR supports explicitly specifying numeric value ids
for instructions, and emits them by default in textual output, now do
the same for blocks.
This is a slightly incompatible change in the textual IR format.
Previously, llvm would parse numeric labels as string names. E.g.
define void @f() {
br label %"55"
55:
ret void
}
defined a label *named* "55", even without needing to be quoted, while
the reference required quoting. Now, if you intend a block label which
looks like a value number to be a name, you must quote it in the
definition too (e.g. `"55":`).
Previously, llvm would print nameless blocks only as a comment, and
would omit it if there was no predecessor. This could cause confusion
for readers of the IR, just as unnamed instructions did prior to the
addition of "%5 = " syntax, back in 2008 (PR2480).
Now, it will always print a label for an unnamed block, with the
exception of the entry block. (IMO it may be better to print it for
the entry-block as well. However, that requires updating many more
tests.)
Thus, the following is supported, and is the canonical printing:
define i32 @f(i32, i32) {
%3 = add i32 %0, %1
br label %4
4:
ret i32 %3
}
New test cases covering this behavior are added, and other tests
updated as required.
Differential Revision: https://reviews.llvm.org/D58548
llvm-svn: 356789
Summary:
With this patch, llgo uses ssautil.Switches
to reconstitute (and synthesise) switches,
which can then be lowered to lookup tables,
trees, etc.
We currently only handle integer const case
switches. We erase the comparison blocks (other
than the initial block), and generate a switch
instruction at the end of the block starting
the if-else-if chain. ssautil.Switches does
not remove duplicate const cases (e.g. same
operands for "||"), so we do this in llgo for
now.
Test Plan: lit test added
Reviewers: pcc
Reviewed By: pcc
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D6831
llvm-svn: 225433
Summary: If a receive case in a select statement is not assigned to a named variable, then we can eliminate the alloca and copy at runtime.
Test Plan: lit test added
Reviewers: pcc
Reviewed By: pcc
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D6785
llvm-svn: 225033
The new ABI is simpler for use cases such as dynamically loaded packages.
The calling convention for import functions is similar to what go/ssa would
produce if BareInits were cleared. However, simply clearing this flag causes
two additional issues:
1) We would need to special case the 'init$guard' variable (see
discussion in https://codereview.appspot.com/78780043/).
2) The call to __go_register_gc_roots needs to appear in the right
place, i.e. after the guard check. Making this check appear
in the right place with non-bare inits seems unreliable at best.
So we keep BareInits set and generate the necessary code manually.
It is still possible to get the old ABI by specifying a path to a gccgo
installation.
Differential Revision: http://reviews.llvm.org/D6804
llvm-svn: 225030
Patch by Andrew Wilkins!
canAvoidElementLoad and canAvoidLoad were incorrectly
eliding loads when an index expression is used as an
another array index expression. This led to a panic.
See comments on https://github.com/go-llvm/llgo/issues/175
Test Plan: lit test added
Differential Revision: http://reviews.llvm.org/D6676
llvm-svn: 224420
If we use the receiver's package, we can end up with identical manglings
for different functions. Consider:
package p
type U struct{}
func (U) f()
package q
import "p"
type T struct { p.U }
func (T) f()
The method set of *T has two synthetic methods named (*T).f(); one forwards to
(T).f(), and the other to (U).f(). Previously, we were distinguishing them
by the receiver's package, and in this case because both methods have the
same receiver, they received the same name.
The methods are correctly distinguished by the package owning the identifier
"f", which is available via f.Object().Pkg().
Differential Revision: http://reviews.llvm.org/D6673
llvm-svn: 224357
James Y Knight