This seems to improve X86's ability to match this into an address computation. Otherwise the other operand gets assigned to the base register and the stack pointer + frame index ends up in the index register. But index registers can't encode ESP/RSP so we end up having to move it into another register to meet the constraint.
I could try to improve the address matcher in X86, but swapping the producer seemed easier. Several other places already have the operands in this order so this is at least consistent.
llvm-svn: 321370
Summary:
Now that store-merge is only generates type-safe stores, do a second
pass just before instruction selection to allow lowered intrinsics to
be merged as well.
Reviewers: jyknight, hfinkel, RKSimon, efriedma, rnk, jmolloy
Subscribers: javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D33675
llvm-svn: 319036
If a vector index is out of bounds, the result is supposed to be
undefined but is not undefined behavior. Change the legalization
for indexing the vector on the stack so that an out of bounds
index does not create an out of bounds memory access.
llvm-svn: 291604
Summary:
One of the vector splitting paths for extract_vector_elt tries to lower:
define i1 @via_stack_bug(i8 signext %idx) {
%1 = extractelement <2 x i1> <i1 false, i1 true>, i8 %idx
ret i1 %1
}
to:
define i1 @via_stack_bug(i8 signext %idx) {
%base = alloca <2 x i1>
store <2 x i1> <i1 false, i1 true>, <2 x i1>* %base
%2 = getelementptr <2 x i1>, <2 x i1>* %base, i32 %idx
%3 = load i1, i1* %2
ret i1 %3
}
However, the elements of <2 x i1> are not byte-addressible. The result of this
is that the getelementptr expands to '%base + %idx * (1 / 8)' which simplifies
to '%base + %idx * 0', and then simply '%base' causing all values of %idx to
extract element zero.
This commit fixes this by promoting the vector elements of <8-bits to i8 before
splitting the vector.
This fixes a number of test failures in pocl.
Reviewers: pekka.jaaskelainen
Subscribers: pekka.jaaskelainen, llvm-commits
Differential Revision: http://reviews.llvm.org/D12591
llvm-svn: 247128
Craig Topper