void bork() {
int *address = 0;
*address = 0;
}
It's compiled into LLVM code that looks like this:
define void @bork() noreturn nounwind {
entry:
unreachable
}
This is bad on some platforms (like PPC) because it will generate the label for
the function but no body. The label could end up being associated with some
non-code related stuff, like a section. This places a "trap" instruction if the
SimplifyCFG pass removed all code from the function leaving only one
"unreachable" instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46387 91177308-0d34-0410-b5e6-96231b3b80d8
promoted functions. This is important for varargs calls in
particular. Thanks to duncan for providing a great testcase.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46108 91177308-0d34-0410-b5e6-96231b3b80d8
drop attributes on varargs call arguments. Also, it could generate
invalid IR if the transformed call already had the 'nest' attribute
somewhere (this can never happen for code coming from llvm-gcc,
but it's a theoretical possibility). Fix both problems.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45973 91177308-0d34-0410-b5e6-96231b3b80d8
byval work. This miscompilation is due to the program indexing an array out
of range and us doing a transformation that broke this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45949 91177308-0d34-0410-b5e6-96231b3b80d8
a load/store of i64. The later prevents promotion/scalarrepl of the
source and dest in many cases.
This fixes the 300% performance regression of the byval stuff on
stepanov_v1p2.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45945 91177308-0d34-0410-b5e6-96231b3b80d8
realize that ne & sgt was a signed comparison (it was only
looking at whether the left compare was signed).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45937 91177308-0d34-0410-b5e6-96231b3b80d8
if this becomes a varargs call then deal correctly with any
parameter attributes on the newly vararg call arguments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45931 91177308-0d34-0410-b5e6-96231b3b80d8
inlining a function if we know that the function does not write
to *any* memory. This implements test/Transforms/Inline/byval2.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45912 91177308-0d34-0410-b5e6-96231b3b80d8
get away with it, which exposes opportunities to eliminate the memory
objects entirely. For example, we now compile byval.ll to:
define internal void @f1(i32 %b.0, i64 %b.1) {
entry:
%tmp2 = add i32 %b.0, 1 ; <i32> [#uses=0]
ret void
}
define i32 @main() nounwind {
entry:
call void @f1( i32 1, i64 2 )
ret i32 0
}
This seems like it would trigger a lot for code that passes around small
structs (e.g. SDOperand's or _Complex)...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45886 91177308-0d34-0410-b5e6-96231b3b80d8
direct calls bails out unless caller and callee have essentially
equivalent parameter attributes. This is illogical - the callee's
attributes should be of no relevance here. Rework the logic, which
incidentally fixes a crash when removed arguments have attributes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45658 91177308-0d34-0410-b5e6-96231b3b80d8
a direct call with cast parameters and cast return
value (if any), instcombine was prepared to cast any
non-void return value into any other, whether castable
or not. Add a new predicate for testing whether casting
is valid, and check it both for the return value and
(as a cleanup) for the parameters.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45657 91177308-0d34-0410-b5e6-96231b3b80d8
things that are not equality comparisons, for example:
(2147479553+4096)-2147479553 < 0 != (2147479553+4096) < 2147479553
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45612 91177308-0d34-0410-b5e6-96231b3b80d8
could theoretically introduce a trap, but is also a performance issue.
This speeds up ptrdist/ks by 8%.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45533 91177308-0d34-0410-b5e6-96231b3b80d8
