RewriteStoreUserOfWholeAlloca deal with tail padding because
isSafeUseOfBitCastedAllocation expects them to. Otherwise, we crash
trying to erase the bitcast.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72688 91177308-0d34-0410-b5e6-96231b3b80d8
method, fixing a crash on PR4146. While the store will
ultimately overwrite the "padded size" number of bits in memory,
the stored value may be a subset of this size. This function
only wants to handle the case where all bits are stored.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71224 91177308-0d34-0410-b5e6-96231b3b80d8
accessed at least once as a vector. This prevents it from
compiling the example in not-a-vector into:
define double @test(double %A, double %B) {
%tmp4 = insertelement <7 x double> undef, double %A, i32 0
%tmp = insertelement <7 x double> %tmp4, double %B, i32 4
%tmp2 = extractelement <7 x double> %tmp, i32 4
ret double %tmp2
}
instead, producing the integer code. Producing vectors when they
aren't otherwise in the program is dangerous because a lot of other
code treats them carefully and doesn't want to break them down.
OTOH, many things want to break down tasty i448's.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63638 91177308-0d34-0410-b5e6-96231b3b80d8
With the new world order, it can handle cases where the first
store into the alloca is an element of the vector, instead of
requiring the first analyzed store to have the vector type
itself. This allows us to un-xfail
test/CodeGen/X86/vec_ins_extract.ll.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63590 91177308-0d34-0410-b5e6-96231b3b80d8
be able to handle *ANY* alloca that is poked by loads and stores of
bitcasts and GEPs with constant offsets. Before the code had a number
of annoying limitations and caused it to miss cases such as storing into
holes in structs and complex casts (as in bitfield-sroa) where we had
unions of bitfields etc. This also handles a number of important cases
that are exposed due to the ABI lowering stuff we do to pass stuff by
value.
One case that is pretty great is that we compile
2006-11-07-InvalidArrayPromote.ll into:
define i32 @func(<4 x float> %v0, <4 x float> %v1) nounwind {
%tmp10 = call <4 x i32> @llvm.x86.sse2.cvttps2dq(<4 x float> %v1)
%tmp105 = bitcast <4 x i32> %tmp10 to i128
%tmp1056 = zext i128 %tmp105 to i256
%tmp.upgrd.43 = lshr i256 %tmp1056, 96
%tmp.upgrd.44 = trunc i256 %tmp.upgrd.43 to i32
ret i32 %tmp.upgrd.44
}
which turns into:
_func:
subl $28, %esp
cvttps2dq %xmm1, %xmm0
movaps %xmm0, (%esp)
movl 12(%esp), %eax
addl $28, %esp
ret
Which is pretty good code all things considering :).
One effect of this is that SROA will start generating arbitrary bitwidth
integers that are a multiple of 8 bits. In the case above, we got a
256 bit integer, but the codegen guys assure me that it can handle the
simple and/or/shift/zext stuff that we're doing on these operations.
This addresses rdar://6532315
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63469 91177308-0d34-0410-b5e6-96231b3b80d8
loads from allocas that cover the entire aggregate. This handles
some memcpy/byval cases that are produced by llvm-gcc. This triggers
a few times in kc++ (with std::pair<std::_Rb_tree_const_iterator
<kc::impl_abstract_phylum*>,bool>) and once in 176.gcc (with %struct..0anon).
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integer to a (transitive) bitcast the alloca and if that integer
has the full size of the alloca, then it clobbers the whole thing.
Handle this by extracting pieces out of the stored integer and
filing them away in the SROA'd elements.
This triggers fairly frequently because the CFE uses integers to
pass small structs by value and the inliner exposes these. For
example, in kimwitu++, I see a bunch of these with i64 stores to
"%struct.std::pair<std::_Rb_tree_const_iterator<kc::impl_abstract_phylum*>,bool>"
In 176.gcc I see a few i32 stores to "%struct..0anon".
In the testcase, this is a difference between compiling test1 to:
_test1:
subl $12, %esp
movl 20(%esp), %eax
movl %eax, 4(%esp)
movl 16(%esp), %eax
movl %eax, (%esp)
movl (%esp), %eax
addl 4(%esp), %eax
addl $12, %esp
ret
vs:
_test1:
movl 8(%esp), %eax
addl 4(%esp), %eax
ret
The second half of this will be to handle loads of the same form.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61853 91177308-0d34-0410-b5e6-96231b3b80d8
