Commit Graph

36 Commits

Author SHA1 Message Date
David Blaikie d288fb8681 [opaque pointer type] Change GetElementPtrInst::getIndexedType to take the pointee type
This pushes the use of PointerType::getElementType up into several
callers - I'll essentially just have to keep pushing that up the stack
until I can eliminate every call to it...

llvm-svn: 233604
2015-03-30 21:41:43 +00:00
Hal Finkel cd5553ed39 [ConstantFold] Don't fold ppc_fp128 <-> int bitcasts
PPC_FP128 is really the sum of two consecutive doubles, where the first double
is always stored first in memory, regardless of the target endianness. The
memory layout of i128, however, depends on the target endianness, and so we
can't fold this without target endianness information. As a result, we must not
do this folding in lib/IR/ConstantFold.cpp (it could be done instead in
Analysis/ConstantFolding.cpp, but that's not done now).

Fixes PR23026.

llvm-svn: 233481
2015-03-28 16:44:57 +00:00
David Majnemer e2a4b856d8 ConstantFold: Fix big shift constant folding
Constant folding for shift IR instructions ignores all bits above 32 of
second argument (shift amount).
Because of that, some undef results are not recognized and APInt can
raise an assert failure if second argument has more than 64 bits.

Patch by Paweł Bylica!

Differential Revision: http://reviews.llvm.org/D7701

llvm-svn: 232176
2015-03-13 16:39:46 +00:00
Mehdi Amini eb242a5041 InstCombine: fix fold "fcmp x, undef" to account for NaN
Summary:
See the two test cases.

; Can fold fcmp with undef on one side by choosing NaN for the undef

; Can fold fcmp with undef on both side
;   fcmp u_pred undef, undef -> true
;   fcmp o_pred undef, undef -> false
; because whatever you choose for the first undef
; you can choose NaN for the other undef

Reviewers: hfinkel, chandlerc, majnemer

Reviewed By: majnemer

Subscribers: majnemer, llvm-commits

Differential Revision: http://reviews.llvm.org/D7617

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231626
2015-03-09 03:20:25 +00:00
Benjamin Kramer 6cd780ff21 Prefer SmallVector::append/insert over push_back loops.
Same functionality, but hoists the vector growth out of the loop.

llvm-svn: 229500
2015-02-17 15:29:18 +00:00
David Majnemer 8b77454dff ConstantFold: Properly fold GEP indices wider than i64
llvm-svn: 229420
2015-02-16 19:10:02 +00:00
David Majnemer 824e011ad7 ConstantFold: Shifting undef by zero results in undef
llvm-svn: 224553
2014-12-18 23:54:43 +00:00
David Majnemer 3729668056 ConstantFold: Clean up X * undef code
No functional change intended.

llvm-svn: 223970
2014-12-10 21:58:17 +00:00
David Majnemer 5a7717e498 ConstantFold, InstSimplify: undef >>a x can be either -1 or 0, choose 0
Zero is usually a nicer constant to have than -1.

llvm-svn: 223969
2014-12-10 21:58:15 +00:00
David Majnemer 89cf6d79eb ConstantFold: an undef shift amount results in undef
X shifted by undef results in undef because the undef value can
represent values greater than the width of the operands.

llvm-svn: 223968
2014-12-10 21:38:05 +00:00
David Majnemer 7b86b77248 ConstantFold: div undef, 0 should fold to undef, not zero
Dividing by zero yields an undefined value.

llvm-svn: 223924
2014-12-10 09:14:55 +00:00
David Majnemer 770fd82f39 ConstantFold: Zero-sized globals might land on top of another global
A zero sized array is zero sized and might share its address with
another global.

llvm-svn: 223684
2014-12-08 19:35:31 +00:00
David Majnemer 64ba326b1e ConstantFold: Don't optimize comparisons with weak linkage objects
Consider:
void f() {}
void __attribute__((weak)) g() {}
bool b = &f != &g;

It's possble for g to resolve to f if --defsym=g=f is passed on to the
linker.

llvm-svn: 223585
2014-12-06 11:58:33 +00:00
David Majnemer ed00cd20ad I didn't intend to commit this change.
llvm-svn: 223584
2014-12-06 10:52:32 +00:00
David Majnemer 1af36e5baf InstSimplify: Optimize away useless unsigned comparisons
Code like X < Y && Y == 0 should always be folded away to false.

llvm-svn: 223583
2014-12-06 10:51:40 +00:00
Sanjay Patel ad8b666624 Return undef on FP <-> Int conversions that overflow (PR21330).
The LLVM Lang Ref states for signed/unsigned int to float conversions:
"If the value cannot fit in the floating point value, the results are undefined."

And for FP to signed/unsigned int:
"If the value cannot fit in ty2, the results are undefined."

This matches the C definitions.

The existing behavior pins to infinity or a max int value, but that may just
lead to more confusion as seen in:
http://llvm.org/bugs/show_bug.cgi?id=21130

Returning undef will hopefully lead to a less silent failure.

Differential Revision: http://reviews.llvm.org/D5603

llvm-svn: 219542
2014-10-10 23:00:21 +00:00
Jiangning Liu 950844fadb Fix a bug around truncating vector in const prop.
In constant folding stage, "TRUNC" can't handle vector data type.

llvm-svn: 216149
2014-08-21 02:12:35 +00:00
Duncan P. N. Exon Smith 0c39d40c8b IR: Don't add inbounds to GEPs of extern_weak variables
Global variables that have `extern_weak` linkage may be null, so it's
incorrect to add `inbounds` when constant folding.

This also fixes a bug when parsing global aliases, whose forward
reference placeholders are global variables with `extern_weak` linkage.
If GEPs to these aliases are encountered before the alias itself, the
GEPs would incorrectly gain the `inbounds` keyword as well.

llvm-svn: 215803
2014-08-16 01:54:32 +00:00
David Majnemer d1bea693e2 IR: Fold away compares between GV GEPs and GVs
A GEP of a non-weak global variable will not be equivalent to another
non-weak global variable or a GEP of such a variable.

Differential Revision: http://reviews.llvm.org/D4238

llvm-svn: 212360
2014-07-04 22:05:26 +00:00
Jingyue Wu baabe5091c Canonicalize addrspacecast ConstExpr between different pointer types
As a follow-up to r210375 which canonicalizes addrspacecast
instructions, this patch canonicalizes addrspacecast constant
expressions.

Given clang uses ConstantExpr::getAddrSpaceCast to emit addrspacecast
cosntant expressions, this patch is also a step towards having the
frontend emit canonicalized addrspacecasts.

Piggyback a minor refactor in InstCombineCasts.cpp

Update three affected tests in addrspacecast-alias.ll,
access-non-generic.ll and constant-fold-gep.ll and added one new test in
constant-fold-address-space-pointer.ll

llvm-svn: 211004
2014-06-15 21:40:57 +00:00
Craig Topper 2617dccea2 [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr.
llvm-svn: 206252
2014-04-15 06:32:26 +00:00
Craig Topper c620761ca5 [C++11] More 'nullptr' conversion or in some cases just using a boolean check instead of comparing to nullptr.
llvm-svn: 205831
2014-04-09 06:08:46 +00:00
Chandler Carruth 03eb0de93d [Modules] Move GetElementPtrTypeIterator into the IR library. As its
name might indicate, it is an iterator over the types in an instruction
in the IR.... You see where this is going.

Another step of modularizing the support library.

llvm-svn: 202815
2014-03-04 10:40:04 +00:00
Nick Lewycky 2d4ba2ebba Fold vector selects with undef elements in the condition. Fixes PR18319.
Patch by Ilia Filippov!

llvm-svn: 198267
2013-12-31 19:30:47 +00:00
Matt Arsenault b03bd4d96b Add addrspacecast instruction.
Patch by Michele Scandale!

llvm-svn: 194760
2013-11-15 01:34:59 +00:00
David Majnemer 3c93dc9f9d IR: Refactor GEP range checks, reuse them for other parts of folding
llvm-svn: 194341
2013-11-10 01:36:22 +00:00
David Majnemer d3d140da36 IR: Properly canonicalize PointerType in ConstantExpr GEPs
No additional test was needed, Other/constant-fold-gep.ll detects this
just fine.

llvm-svn: 194221
2013-11-07 22:29:42 +00:00
David Majnemer bd4fef4a89 IR: Do not canonicalize constant GEPs into an out-of-bounds array access
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

llvm-svn: 194220
2013-11-07 22:15:53 +00:00
Matt Arsenault 130e0ef6f4 Respect address space sizes in isEliminableCastPair.
This avoids constant folding bitcast/ptrtoint/inttoptr combinations
that have illegal bitcasts between differently sized address spaces.

llvm-svn: 187455
2013-07-30 22:27:10 +00:00
Benjamin Kramer cc846016bf ConstantFold: Check that truncating the other side is safe under a sext when trying to remove a sext from a compare.
Fixes PR16462.

llvm-svn: 185284
2013-06-30 13:47:43 +00:00
Meador Inge 9b47f6414b IR: Don't constant fold GEP bitcasts between different address spaces
PR15262 reported a bug where the following instruction:

  i8 getelementptr inbounds i8* bitcast ([4 x i8] addrspace(12)* @buf to i8*),
                                i32 2

was getting folded into:

  addrspace(12)* getelementptr inbounds ([4 x i8] addrspace(12)* @buf, i32 0,
                                        i32 2)

This caused instcombine to crash because the original instruction and
the folded instruction have different types.  The issue was fixed by
disallowing bitcasts between different address spaces to be folded away.

llvm-svn: 176156
2013-02-27 02:26:42 +00:00
Nadav Rotem 0e48803252 Fix a bug that was found by the clang static analyzer. The var "AT" is null so we cant deref it.
llvm-svn: 175550
2013-02-19 19:36:59 +00:00
Dan Gohman 6a61fccb96 Fix ConstantFold's folding of icmp instructions to recognize that,
for example, a one-past-the-end pointer from one global variable may
be equal to the base pointer of another global variable.

llvm-svn: 173995
2013-01-31 00:01:45 +00:00
Tim Northover 29178a348a Make APFloat constructor require explicit semantics.
Previously we tried to infer it from the bit width size, with an added
IsIEEE argument for the PPC/IEEE 128-bit case, which had a default
value. This default value allowed bugs to creep in, where it was
inappropriate.

llvm-svn: 173138
2013-01-22 09:46:31 +00:00
Chandler Carruth 9fb823bbd4 Move all of the header files which are involved in modelling the LLVM IR
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

llvm-svn: 171366
2013-01-02 11:36:10 +00:00
Chandler Carruth ef860a2488 Rename VMCore directory to IR.
Aside from moving the actual files, this patch only updates the build
system and the source file comments under lib/... that are relevant.

I'll be updating other docs and other files in smaller subsequnet
commits.

While I've tried to test this, but it is entirely possible that there
will still be some build system fallout.

Also, note that I've not changed the library name itself: libLLVMCore.a
is still the library name. I'd be interested in others' opinions about
whether we should rename this as well (I think we should, just not sure
what it might break)

llvm-svn: 171359
2013-01-02 09:10:48 +00:00