LowerSubregs, and fix an x86-64 isel bug that this exposed.
SUBREG_TO_REG for x86-64 implicit zero extension is only safe for
isel to generate when the source is known to always have zeros in
the high 32 bits. The EXTRACT_SUBREG instruction does not clear
the high 32 bits.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54444 91177308-0d34-0410-b5e6-96231b3b80d8
subreg form on x86-64, to avoid the problem with x86-32
having GPRs that don't have 8-bit subregs.
Also, change several 16-bit instructions to use
equivalent 32-bit instructions. These have a smaller
encoding and avoid partial-register updates.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54223 91177308-0d34-0410-b5e6-96231b3b80d8
which is represented in codegen as an 'and' operation. This matches them
with movz instructions, instead of leaving them to be matched by and
instructions with an immediate field.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54147 91177308-0d34-0410-b5e6-96231b3b80d8
parallel its analogue, Value::value_use_iterator. The operator* method
now returns the user, rather than the use.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54127 91177308-0d34-0410-b5e6-96231b3b80d8
mmx needs its own fancy shuffle logic based on unpack; for now we get correct but awful code.
Also commit Mon Ping's VSETCC patch
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54039 91177308-0d34-0410-b5e6-96231b3b80d8
that include useful information like the name of the
block being viewed and the current phase of compilation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53872 91177308-0d34-0410-b5e6-96231b3b80d8
generic SDNode's (nodes with their own constructors
should do sanity checking in the constructor). Add
sanity checks for BUILD_VECTOR and fix all the places
that were producing bogus BUILD_VECTORs, as found by
"make check". My favorite is the BUILD_VECTOR with
only two operands that was being used to build a
vector with four elements!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53850 91177308-0d34-0410-b5e6-96231b3b80d8
replacement of multiple values. This is slightly more efficient
than doing multiple ReplaceAllUsesOfValueWith calls, and theoretically
could be optimized even further. However, an important property of this
new function is that it handles the case where the source value set and
destination value set overlap. This makes it feasible for isel to use
SelectNodeTo in many very common cases, which is advantageous because
SelectNodeTo avoids a temporary node and it doesn't require CSEMap
updates for users of values that don't change position.
Revamp MorphNodeTo, which is what does all the work of SelectNodeTo, to
handle operand lists more efficiently, and to correctly handle a number
of corner cases to which its new wider use exposes it.
This commit also includes a change to the encoding of post-isel opcodes
in SDNodes; now instead of being sandwiched between the target-independent
pre-isel opcodes and the target-dependent pre-isel opcodes, post-isel
opcodes are now represented as negative values. This makes it possible
to test if an opcode is pre-isel or post-isel without having to know
the size of the current target's post-isel instruction set.
These changes speed up llc overall by 3% and reduce memory usage by 10%
on the InstructionCombining.cpp testcase with -fast and -regalloc=local.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53728 91177308-0d34-0410-b5e6-96231b3b80d8
