Because the builtin longjmp implementation uses a CTR-based indirect jump, when
the control flow arrives at the builtin setjmp call, the CTR register has
necessarily been clobbered. Correspondingly, this adds CTR to the list of
implicit definitions of the builtin setjmp pseudo instruction.
We don't need to add CTR to the implicit definitions of builtin longjmp
because, even though it does clobber the CTR register, the control flow cannot
return to inside the loop unless there is also a builtin setjmp call.
llvm-svn: 186488
Rename's documentation says "Files are renamed as if by POSIX rename()". and it
is used for atomically updating output files from a temporary. Having rename
fallback to a non atomic copy has the potential to hide bugs, like using
a temporary file in /tmp instead of a unique name next to the final destination.
llvm-svn: 186483
This builds on some frame-lowering code that has existed since 2005 (r24224)
but was disabled in 2008 (r48188) because it needed base pointer support to
function correctly. This implementation follows the strategy suggested by Dale
Johannesen in r48188 where the following comment was added:
This does not currently work, because the delta between old and new stack
pointers is added to offsets that reference incoming parameters after the
prolog is generated, and the code that does that doesn't handle a variable
delta. You don't want to do that anyway; a better approach is to reserve
another register that retains to the incoming stack pointer, and reference
parameters relative to that.
And now we do exactly that. If we don't need a frame pointer, then we use r31
as a base pointer. If we do need a frame pointer, then we use r30 as a base
pointer. The base pointer retains the value of the stack pointer before it was
decremented in the prologue. We then use the base pointer to resolve all
negative frame indicies. The basic scheme follows that for base pointers in the
X86 backend.
We use a base pointer when we need to dynamically realign the incoming stack
pointer. This currently applies only to static objects (dynamic allocas with
large alignments, and base-pointer support in SjLj lowering will come in future
commits).
llvm-svn: 186478
This check does not always work because not all of the GEPs use a constant offset, but it happens often enough to reduce the number of times we use SCEV.
llvm-svn: 186465
block. Blocks that have an indirect branch terminator, even if it's not the
last terminator, should still be treated as unanalyzable.
<rdar://problem/14437274>
Reducing a useful regression test case is proving difficult - I hope to have
one soon.
llvm-svn: 186461
This adds an instruction alias to make the assembler recognize the alternate literal form: pli [PC, #+/-<imm>]
See A8.8.129 in the ARM ARM (DDI 0406C.b).
Fixes <rdar://problem/14403733>.
llvm-svn: 186459
These floats all represented block frequencies anyway, so just use the
BlockFrequency class directly.
Some floating point computations remain in tryLocalSplit(). They are
estimating spill weights which are still floats.
llvm-svn: 186435
Original commit message:
Remove floating point computations from SpillPlacement.cpp.
Patch by Benjamin Kramer!
Use the BlockFrequency class instead of floats in the Hopfield network
computations. This rescales the node Bias field from a [-2;2] float
range to two block frequencies BiasN and BiasP pulling in opposite
directions. This construct has a more predictable behavior when block
frequencies saturate.
The per-node scaling factors are no longer necessary, assuming the block
frequencies around a bundle are consistent.
This patch can cause the register allocator to make different spilling
decisions. The differences should be small.
llvm-svn: 186434
Use PMIN/PMAX for UGE/ULE vector comparions to reduce the number of required
instructions. This trick also works for UGT/ULT, but there is no advantage in
doing so. It wouldn't reduce the number of instructions and it would actually
reduce performance.
Reviewer: Ben
radar:5972691
llvm-svn: 186432
This is to support parsing UTF16 response files in LLVM/lib/Option for
lld and clang.
Reviewers: hans
Differential Revision: http://llvm-reviews.chandlerc.com/D1138
llvm-svn: 186426
For safety, the inliner cannot decrease the allignment on an alloca when
merging it with another.
I've included two variants of the test case for this: one with DataLayout
available, and one without. When DataLayout is not available, if only one of
the allocas uses the default alignment (getAlignment() == 0), then they cannot
be safely merged.
llvm-svn: 186425
When truncating to a format with fewer mantissa bits, APFloat::convert
will perform a right shift of the mantissa by the difference of the
precision of the two formats. Usually, this will result in just the
mantissa bits needed for the target format.
One special situation is if the input number is denormal. In this case,
the right shift may discard significant bits. This is usually not a
problem, since truncating a denormal usually results in zero (underflow)
after normalization anyway, since the result format's exponent range is
usually smaller than the target format's.
However, there is one case where the latter property does not hold:
when truncating from ppc_fp128 to double. In particular, truncating
a ppc_fp128 whose first double of the pair is denormal should result
in just that first double, not zero. The current code however
performs an excessive right shift, resulting in lost result bits.
This is then caught in the APFloat::normalize call performed by
APFloat::convert and causes an assertion failure.
This patch checks for the scenario of truncating a denormal, and
attempts to (possibly partially) replace the initial mantissa
right shift by decrementing the exponent, if doing so will still
result in a valid *target format* exponent.
Index: test/CodeGen/PowerPC/pr16573.ll
===================================================================
--- test/CodeGen/PowerPC/pr16573.ll (revision 0)
+++ test/CodeGen/PowerPC/pr16573.ll (revision 0)
@@ -0,0 +1,11 @@
+; RUN: llc < %s | FileCheck %s
+
+target triple = "powerpc64-unknown-linux-gnu"
+
+define double @test() {
+ %1 = fptrunc ppc_fp128 0xM818F2887B9295809800000000032D000 to double
+ ret double %1
+}
+
+; CHECK: .quad -9111018957755033591
+
Index: lib/Support/APFloat.cpp
===================================================================
--- lib/Support/APFloat.cpp (revision 185817)
+++ lib/Support/APFloat.cpp (working copy)
@@ -1956,6 +1956,23 @@
X86SpecialNan = true;
}
+ // If this is a truncation of a denormal number, and the target semantics
+ // has larger exponent range than the source semantics (this can happen
+ // when truncating from PowerPC double-double to double format), the
+ // right shift could lose result mantissa bits. Adjust exponent instead
+ // of performing excessive shift.
+ if (shift < 0 && isFiniteNonZero()) {
+ int exponentChange = significandMSB() + 1 - fromSemantics.precision;
+ if (exponent + exponentChange < toSemantics.minExponent)
+ exponentChange = toSemantics.minExponent - exponent;
+ if (exponentChange < shift)
+ exponentChange = shift;
+ if (exponentChange < 0) {
+ shift -= exponentChange;
+ exponent += exponentChange;
+ }
+ }
+
// If this is a truncation, perform the shift before we narrow the storage.
if (shift < 0 && (isFiniteNonZero() || category==fcNaN))
lostFraction = shiftRight(significandParts(), oldPartCount, -shift);
llvm-svn: 186409
We'd forgotten to provide string representations for the special ARMISD atomic
nodes; this adds them in. No effect on CodeGen, just makes the output of
"-view-whatever-dags" slightly more readable.
llvm-svn: 186406
Another patch in the series to make more use of R.SBG. This one extends
r186072 and r186073 to handle cases where the AND is inside the shift.
llvm-svn: 186399
This patch enables calls to __aeabi_idivmod when in EABI mode,
by using the remainder value returned on registers (R1),
enabled by the ARM triple "none-eabi". Note that Darwin and
GNUEABI triples will continue lowering on GNU style, that is,
using the stack for the remainder.
Still need to add SREM/UREM support fix for 64-bit lowering.
llvm-svn: 186390
