ARM prologues usually look like:
push {r7, lr}
sub sp, sp, #4
If code size is extremely important, this can be optimised to the single
instruction:
push {r6, r7, lr}
where we don't actually care about the contents of r6, but pushing it subtracts
4 from sp as a side effect.
This should implement such a conversion, predicated on the "minsize" function
attribute (-Oz) since I've yet to find any code it actually makes faster.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194264 91177308-0d34-0410-b5e6-96231b3b80d8
Linux cannot open directories with open(2), although cygwin and *bsd can.
Motivation: The test, Object/directory.ll, had been failing with --target=cygwin on Linux. XFAIL was improper for host issues.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194257 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Consider a GEP of:
i8* getelementptr ({ [2 x i8], i32, i8, [3 x i8] }* @main.c, i32 0, i32 0, i64 0)
If we proceeded to GEP the aforementioned object by 8, would form a GEP of:
i8* getelementptr ({ [2 x i8], i32, i8, [3 x i8] }* @main.c, i32 0, i32 0, i64 8)
Note that we would go through the first array member, causing an
out-of-bounds accesses. This is problematic because we might get fooled
if we are trying to evaluate loads using this GEP, for example, based
off of an object with a constant initializer where the array is zero.
This fixes PR17732.
Reviewers: nicholas, chandlerc, void
Reviewed By: void
CC: llvm-commits, echristo, void, aemerson
Differential Revision: http://llvm-reviews.chandlerc.com/D2093
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194220 91177308-0d34-0410-b5e6-96231b3b80d8
Patch by Michele Scandale!
Rewrite of the functions used to compute the backedge taken count of a
loop on LT and GT comparisons.
I decided to split the handling of LT and GT cases becasue the trick
"a > b == -a < -b" in some cases prevents the trip count computation
due to the multiplication by -1 on the two operands of the
comparison. This issue comes from the conservative computation of
value range of SCEVs: taking the negative SCEV of an expression that
have a small positive range (e.g. [0,31]), we would have a SCEV with a
fullset as value range.
Indeed, in the new rewritten function I tried to better handle the
maximum backedge taken count computation when MAX/MIN expression are
used to handle the cases where no entry guard is found.
Some test have been modified in order to check the new value correctly
(I manually check them and reasoning on possible overflow the new
values seem correct).
I finally added a new test case related to the multiplication by -1
issue on GT comparisons.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194116 91177308-0d34-0410-b5e6-96231b3b80d8
MorphNodeTo is not safe to call during DAG building. It eagerly
deletes dependent DAG nodes which invalidates the NodeMap. We could
expose a safe interface for morphing nodes, but I don't think it's
worth it. Just create a new MachineNode and replaceAllUsesWith.
My understaning of the SD design has been that we want to support
early target opcode selection. That isn't very well supported, but
generally works. It seems reasonable to rely on this feature even if
it isn't widely used.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194102 91177308-0d34-0410-b5e6-96231b3b80d8
Cortex-M0 supports these 32-bit instructions despite being Thumb1 only
(mostly). We knew about that but not that the aliases without the default "sy"
operand were also permitted.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194094 91177308-0d34-0410-b5e6-96231b3b80d8
Due to the previously added overflow checks, we can have a retain/release
relation that is one directional. This occurs specifically when we run into an
additive overflow causing us to drop state in only one direction. If that
occurs, we should bail and not optimize that retain/release instead of
asserting.
Apologies for the size of the testcase. It is necessary to cause the additive
cfg overflow to trigger.
rdar://15377890
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194083 91177308-0d34-0410-b5e6-96231b3b80d8
Submit the basic port of the rest of ARM constant islands code to Mips.
Two test cases are added which reflect the next level of functionality:
constants getting moved to water areas that are out of range from the
initial placement at the end of the function and basic blocks being split to
create water when none exists that can be used. There is a bunch of this
code that is not complete and has been marked with IN_PROGRESS. I will
finish cleaning this all up during the next week or two and submit the
rest of the test cases. I have elminated some code for dealing with
inline assembly because to me it unecessarily complicates things and
some of the newer features of llvm like function attributies and builtin
assembler give me better tools to solve the alignment issues created
there. Also, for Mips16 I even have the option of not doing constant
islands in the present of inline assembler if I chose. When everything
has been completed I will summarize the port and notify people that
are knowledgable regarding the ARM Constant Islands code so they can
review it in it's entirety if they wish.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194053 91177308-0d34-0410-b5e6-96231b3b80d8
If an inline assembly operand has multiple constraints (e.g. "Ir" for immediate
or register) and an operand modifier (E.g. "w" for "print register as wN") then
we need to decide behaviour when the modifier doesn't apply to the constraint.
Previousely produced some combination of an assertion failure and a fatal
error. GCC's behaviour appears to be to ignore the modifier and print the
operand in the default way. This patch should implement that.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194024 91177308-0d34-0410-b5e6-96231b3b80d8
When the elements are extracted from a select on vectors
or a vector select, do the select on the extracted scalars
from the input if there is only one use.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194013 91177308-0d34-0410-b5e6-96231b3b80d8
In order to create an ObjectFile implementation that uses bitcode files, we
need to propagate the bitcode errors to the ObjectFile interface, so we need
to convert it to use the same error handling as ObjectFile: error_code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193996 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r193356, it caused PR17781.
A reduced test case covering this regression has been added to the test suite.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193955 91177308-0d34-0410-b5e6-96231b3b80d8
