Option: -mllvm -warn-stack-size=<limit>
Output (if limit is exceeded):
warning: Stack size limit exceeded (<actual size>) in <functionName>.
The longer term plan is to hook that to a clang warning.
PR:4072
<rdar://problem/13987214>
llvm-svn: 183552
Fix an assertion when the compiler encounters big constants whose bit width is
not a multiple of 64-bits.
Although clang would never generate something like this, the backend should be
able to handle any legal IR.
<rdar://problem/13363576>
llvm-svn: 183544
OpenBSD's stack smashing protection differs slightly from other
platforms:
1. The smash handler function is "__stack_smash_handler(const char
*funcname)" instead of "__stack_chk_fail(void)".
2. There's a hidden "long __guard_local" object that gets linked
into each executable and DSO.
Patch by Matthew Dempsky.
llvm-svn: 183533
Add earlyclobber constaints to prevent input register being allocated as
the output register because, according to Intel spec [1], "If any pair
of the index, mask, or destination registers are the same, this
instruction results a UD fault."
---
[1] http://software.intel.com/sites/default/files/319433-014.pdf
llvm-svn: 183327
The MOV64ri64i32 instruction required hacky MCInst lowering because it
was allocated as setting a GR64, but the eventual instruction ("movl")
only set a GR32. This converts it into a so-called "MOV32ri64" which
still accepts a (appropriate) 64-bit immediate but defines a GR32.
This is then converted to the full GR64 by a SUBREG_TO_REG operation,
thus keeping everyone happy.
This fixes a typo in the opcode field of the original patch, which
should make the legact JIT work again (& adds test for that problem).
llvm-svn: 183068
Namely, check if the target allows to fold more that one register in the
addressing mode and if yes, adjust the cost accordingly.
Prior to this commit, reg1 + scale * reg2 accesses were artificially preferred
to reg1 + reg2 accesses. Indeed, the cost model wrongly assumed that reg1 + reg2
needs a temporary register for the computation, whereas it was correctly
estimated for reg1 + scale * reg2.
<rdar://problem/13973908>
llvm-svn: 183021
The MOV64ri64i32 instruction required hacky MCInst lowering because it was
allocated as setting a GR64, but the eventual instruction ("movl") only set a
GR32. This converts it into a so-called "MOV32ri64" which still accepts a
(appropriate) 64-bit immediate but defines a GR32. This is then converted to
the full GR64 by a SUBREG_TO_REG operation, thus keeping everyone happy.
llvm-svn: 182991
The pattern the test originally checked for doesn't occur on other -mcpu
settings. On atom it's still there though slightly differently scheduled.
llvm-svn: 182933
This test was failing on some hosts when an unexpected register was used for a
variable. This just extends the regexp to allow the new x86-64 registers.
llvm-svn: 182929
Instead of having a bunch of separate MOV8r0, MOV16r0, ... pseudo-instructions,
it's better to use a single MOV32r0 (which will expand to "xorl %reg, %reg")
and obtain other sizes with EXTRACT_SUBREG and SUBREG_TO_REG. The encoding is
smaller and partial register updates can sometimes be avoided.
Until recently, this sequence was a barrier to rematerialization though. That
should now be fixed so it's an appropriate time to make the change.
llvm-svn: 182928
Fixes PR16146: gdb.base__call-ar-st.exp fails after
pre-RA-sched=source fixes.
Patch by Xiaoyi Guo!
This also fixes an unsupported dbg.value test case. Codegen was
previously incorrect but the test was passing by luck.
llvm-svn: 182885
When -ffast-math is in effect (on Linux, at least), clang defines
__FINITE_MATH_ONLY__ > 0 when including <math.h>. This causes the
preprocessor to include <bits/math-finite.h>, which renames the sqrt functions.
For instance, "sqrt" is renamed as "__sqrt_finite".
This patch adds the 3 new names in such a way that they will be treated
as equivalent to their respective original names.
llvm-svn: 182739
Other than recognizing the attribute, the patch does little else.
It changes the branch probability analyzer so that edges into
blocks postdominated by a cold function are given low weight.
Added analysis and code generation tests. Added documentation for the
new attribute.
llvm-svn: 182638
The peephole tries to reorder MOV32r0 instructions such that they are
before the instruction that modifies EFLAGS.
The problem is that the peephole does not consider the case where the
instruction that modifies EFLAGS also depends on the previous state of
EFLAGS.
Instead, walk backwards until we find an instruction that has a def for
EFLAGS but does not have a use.
If we find such an instruction, insert the MOV32r0 before it.
If it cannot find such an instruction, skip the optimization.
llvm-svn: 182184
Shuffles that only move an element into position 0 of the vector are common in
the output of the loop vectorizer and often generate suboptimal code when SSSE3
is not available. Lower them to vector shifts if possible.
We still prefer palignr over psrldq because it has higher throughput on
sandybridge.
llvm-svn: 182102
Increase the number of instructions LLVM recognizes as setting the ZF
flag. This allows us to remove test instructions that redundantly
recalculate the flag.
llvm-svn: 181937
IR optimisation passes can result in a basic block that contains:
llvm.lifetime.start(%buf)
...
llvm.lifetime.end(%buf)
...
llvm.lifetime.start(%buf)
Before this change, calculateLiveIntervals() was ignoring the second
lifetime.start() and was regarding %buf as being dead from the
lifetime.end() through to the end of the basic block. This can cause
StackColoring to incorrectly merge %buf with another stack slot.
Fix by removing the incorrect Starts[pos].isValid() and
Finishes[pos].isValid() checks.
Just doing:
Starts[pos] = Indexes->getMBBStartIdx(MBB);
Finishes[pos] = Indexes->getMBBEndIdx(MBB);
unconditionally would be enough to fix the bug, but it causes some
test failures due to stack slots not being merged when they were
before. So, in order to keep the existing tests passing, treat LiveIn
and LiveOut separately rather than approximating the live ranges by
merging LiveIn and LiveOut.
This fixes PR15707.
Patch by Mark Seaborn.
llvm-svn: 181922
We generate a `push' of a random register (%rax) if the stack needs to be
aligned by the size of that register. However, this could mess up compact unwind
generation. In particular, we want to still generate compact unwind in the
presence of this monstrosity.
Check if the push of of the %rax/%eax register. If it is and it's marked with
the `FrameSetup' flag, then we can generate a compact unwind encoding for the
function only if the push is the last FrameSetup instruction.
llvm-svn: 181540
