On z/OS there is a hard limitation on on the maximum requestable alignment in aligned attribute for static variables. We need to truncate values greater than that.
Reviewed By: abhina.sreeskantharajan
Differential Revision: https://reviews.llvm.org/D98864
Zero length bitfield alignment is not respected if they are leading members on z/OS target.
Reviewed By: abhina.sreeskantharajan
Differential Revision: https://reviews.llvm.org/D98890
Recognize BI__builtin_isinf and BI__builtin_isfinite (and a few other opcodes
for finite) in testFPKind() and handle with TDC.
Review: Ulrich Weigand.
Differential Revision: https://reviews.llvm.org/D97901
The recent commit 00a6254 "Stop traping on sNaN in builtin_isnan" changed the
lowering in constrained FP mode of builtin_isnan from an FP comparison to
integer operations to avoid trapping.
SystemZ has a special instruction "Test Data Class" which is the preferred
way to do this check. This patch adds a new target hook "testFPKind()" that
lets SystemZ emit the s390_tdc intrinsic instead.
testFPKind() takes the BuiltinID as an argument and is expected to soon
handle more opcodes than just 'builtin_isnan'.
Review: Thomas Preud'homme, Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D96568
vec_xl() and vec_xst() should not emit alignment hints since they take a
scalar pointer and also add a byte offset if passed.
This patch uses memcpy to achieve the desired result.
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D96471
For a default visibility external linkage definition, dso_local is set for ELF
-fno-pic/-fpie and COFF and Mach-O. Since default clang -cc1 for ELF is similar
to -fpic ("PIC Level" is not set), this nuance causes unneeded binary format differences.
To make emitted IR similar, ELF -cc1 -fpic will default to -fno-semantic-interposition,
which sets dso_local for default visibility external linkage definitions.
To make this flip smooth and enable future (dso_local as definition default),
this patch replaces (function) `define ` with `define{{.*}} `,
(variable/constant/alias) `= ` with `={{.*}} `, or inserts appropriate `{{.*}} `.
This patch updates IRBuilder to create insertelement/shufflevector using poison as a placeholder.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D93793
Currently undef is used as a don’t-care vector when constructing a vector using a series of insertelement.
However, this is problematic because undef isn’t undefined enough.
Especially, a sequence of insertelement can be optimized to shufflevector, but using undef as its placeholder makes shufflevector a poison-blocking instruction because undef cannot be optimized to poison.
This makes a few straightforward optimizations incorrect, such as:
```
; https://bugs.llvm.org/show_bug.cgi?id=44185
define <4 x float> @insert_not_undef_shuffle_translate_commute(float %x, <4 x float> %y, <4 x float> %q) {
%xv = insertelement <4 x float> %q, float %x, i32 2
%r = shufflevector <4 x float> %y, <4 x float> %xv, <4 x i32> { 0, 6, 2, undef }
ret <4 x float> %r ; %r[3] is undef
}
=>
define <4 x float> @insert_not_undef_shuffle_translate_commute(float %x, <4 x float> %y, <4 x float> %q) {
%r = insertelement <4 x float> %y, float %x, i32 1
ret <4 x float> %r ; %r[3] = %y[3], incorrect if %y[3] = poison
}
Transformation doesn't verify!
ERROR: Target is more poisonous than source
```
I’d like to suggest
1. Using poison as insertelement’s placeholder value (IRBuilder::CreateVectorSplat should be patched too)
2. Updating shufflevector’s semantics to return poison element if mask is undef
Note that poison is currently lowered into UNDEF in SelDag, so codegen part is okay.
m_Undef() matches PoisonValue as well, so existing optimizations will still fire.
The only concern is hidden miscompilations that will go incorrect when poison constant is given.
A conservative way is copying all tests having `insertelement undef` & replacing it with `insertelement poison` & run Alive2 on it, but it will create many tests and people won’t like it. :(
Instead, I’ll simply locally maintain the tests and run Alive2.
If there is any bug found, I’ll report it.
Relevant links: https://bugs.llvm.org/show_bug.cgi?id=43958 , http://lists.llvm.org/pipermail/llvm-dev/2019-November/137242.html
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D93586
The dependency mechanism for C has been implemented, and we have rolled out
this to all internal users, didn't see crashy issues, we consider it is stable
enough.
Differential Revision: https://reviews.llvm.org/D89046
This patch creates a SystemZ folder in clang/test/CodeGen to contain systemz-related lit tests.
Reviewed By: muiez
Differential Revision: https://reviews.llvm.org/D91628
Fanbo Meng