Commit Graph

4 Commits

Author SHA1 Message Date
Francis Visoiu Mistrih 25528d6de7 [CodeGen] Unify MBB reference format in both MIR and debug output
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.

The MIR printer prints the IR name of a MBB only for block definitions.

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix

Differential Revision: https://reviews.llvm.org/D40422

llvm-svn: 319665
2017-12-04 17:18:51 +00:00
David Majnemer 011980cd50 [X86] Add intrinsics for reading and writing to the flags register
LLVM's targets need to know if stack pointer adjustments occur after the
prologue.  This is needed to correctly determine if the red-zone is
appropriate to use or if a frame pointer is required.

Normally, LLVM can figure this out very precisely by reasoning about the
contents of the MachineFunction.  There is an interesting corner case:
inline assembly.

The vast majority of inline assembly which will perform a push or pop is
done so to pair up with pushf or popf as appropriate.  Unfortunately,
this inline assembly doesn't mark the stack pointer as clobbered
because, well, it isn't.  The stack pointer is decremented and then
immediately incremented.  Because of this, LLVM was changed in r256456
to conservatively assume that inline assembly contain a sequence of
stack operations.  This is unfortunate because the vast majority of
inline assembly will not end up manipulating the stack pointer in any
way at all.

Instead, let's provide a more principled solution: an intrinsic.
FWIW, other compilers (MSVC and GCC among them) also provide this
functionality as an intrinsic.

llvm-svn: 256685
2016-01-01 06:50:01 +00:00
David Majnemer 334676355a [X86, Win64] Use a frame pointer if pushf is emitted
A frame pointer must be used if stack pointer is modified after the
prologue.  LLVM will emit pushf/popf if we need to save/restore the
FLAGS register, requiring us to have a frame pointer for the function.

There is a small twist: this sequence might exist in user code via
inline-assembly.  For now, conservatively assume that such functions
require a frame pointer.  For real world justification, please see
clang's implementation of __readeflags.

This fixes PR25945.

llvm-svn: 256456
2015-12-27 06:07:26 +00:00
Simon Pilgrim 96cbce61b2 [X86][SSE] Legal XMM Register Class ordering for SSE1
It turns out we have a number of places that just grab the first type attached to a register class for various reasons. This is fine unless for some reason that type isn't legal on the current target, such as for SSE1 which doesn't support v16i8/v8i16/v4i32/v2i64 - all of which were included before 4f32 in the class.

Given that this is such a rare situation I've just re-ordered the types and placed the float types first.

Fix for PR16133

Differential Revision: http://reviews.llvm.org/D14787

llvm-svn: 253773
2015-11-21 12:38:34 +00:00