This improves the X86 cost model for small constants with large types. Before
this commit we would even hoist trivial constants such as i96 2.
This is related to <rdar://problem/17070936>
llvm-svn: 210504
This commit starts with a "git mv ARM64 AArch64" and continues out
from there, renaming the C++ classes, intrinsics, and other
target-local objects for consistency.
"ARM64" test directories are also moved, and tests that began their
life in ARM64 use an arm64 triple, those from AArch64 use an aarch64
triple. Both should be equivalent though.
This finishes the AArch64 merge, and everyone should feel free to
continue committing as normal now.
llvm-svn: 209577
Currently the X86 backend doesn't support types larger than i128 very well. For
example an i192 multiply will assert in codegen when the 2nd argument is a constant and the constant got hoisted.
This fix changes the cost model to never hoist constants for types larger than
i128. Once the codegen issues have been resolved, the cost model can be updated
to allow also larger types.
This is related to <rdar://problem/16954938>
llvm-svn: 209162
There is no need to check if we want to hoist the immediate value of an
shift instruction. Simply return TCC_Free right away.
This change is like r206101, but for X86.
rdar://problem/16190769
llvm-svn: 207692
In the case where the constant comes from a cloned cast instruction, the
materialization code has to go before the cloned cast instruction.
This commit fixes the method that finds the materialization insertion point
by making it aware of this case.
This fixes <rdar://problem/15532441>
llvm-svn: 206913
Implements the various TTI functions to enable constant hoisting on PPC. The
only significant test-suite change is this:
MultiSource/Benchmarks/VersaBench/bmm/bmm - 20% speedup
(which essentially reverses the slowdown from r206120).
llvm-svn: 206141
Originally the cost model would give up for large constants and just return the
maximum cost. This is not what we want for constant hoisting, because some of
these constants are large in bitwidth, but are still cheap to materialize.
This commit fixes the cost model to either return TCC_Free if the cost cannot be
determined, or accurately calculate the cost even for large constants
(bitwidth > 128).
This fixes <rdar://problem/16591573>.
llvm-svn: 206100
The immediate cost calculation code was hitting an assertion in the included
test case, because APInt was still internally 128-bits. Truncating it to 64-bits
fixed the issue.
Fixes <rdar://problem/16572521>.
llvm-svn: 205947
This implements the target-hooks for ARM64 to enable constant hoisting.
This fixes <rdar://problem/14774662> and <rdar://problem/16381500>.
llvm-svn: 205791
A PHI node usually has only one value/basic block pair per incoming basic block.
In the case of a switch statement it is possible that a following PHI node may
have more than one such pair per incoming basic block. E.g.:
%0 = phi i64 [ 123456, %case2 ], [ 654321, %Entry ], [ 654321, %Entry ]
This is valid and the verfier doesn't complain, because both values are the
same.
Constant hoisting materializes the constant for each operand separately and the
value is still the same, but the variable names have changed. As a result the
verfier can't recognize anymore that they are the same value and complains.
This fix adds special update code for PHI node in constant hoisting to prevent
this corner case.
This fixes <rdar://problem/16394449>
llvm-svn: 204537
Extend the target hook to take also the operand index into account when
calculating the cost of the constant materialization.
Related to <rdar://problem/16381500>
llvm-svn: 204435
Originally the algorithm would search for expensive constants and track their
users, which could be instructions and constant expressions. This change only
tracks the constants for instructions, but constant expressions are indirectly
covered too. If an operand is an constant expression, then we look through the
expression to find anny expensive constants.
The algorithm keep now track of the instruction and the operand index where the
constant is used. This allows more precise hoisting of constant materialization
code for PHI instructions, because we only hoist to the basic block of the
incoming operand. Before we had to find the idom of all PHI operands and hoist
the materialization code there.
This also makes updating of instructions easier. Before we had to keep track of
the original constant, find it in the instructions, and then replace it. Now we
can just simply update the operand.
Related to <rdar://problem/16381500>
llvm-svn: 204433
This commit extends the coverage of the constant hoisting pass, adds additonal
debug output and updates the function names according to the style guide.
Related to <rdar://problem/16381500>
llvm-svn: 204389
The bitcast instruction during constant materialization was not placed correcly
in the presence of phi nodes. This commit fixes the insertion point to be in the
idom instead.
This fixes PR18768
llvm-svn: 201009
Juergen Ributzka