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author | Chris Lattner <sabre@nondot.org> | 2011-04-18 06:22:33 +0000 |
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committer | Chris Lattner <sabre@nondot.org> | 2011-04-18 06:22:33 +0000 |
commit | 1518afddea6c0a4275a9ac64a9ffe2b6b4c0600a (patch) | |
tree | f09998e754d0346e63168c3547b3d67c2c9fc880 /docs/ProgrammersManual.html | |
parent | 1023643d501b4375b261eb5449a2bb0195f49780 (diff) |
Implement major new fastisel functionality: the matcher can now handle immediates with
value constraints on them (when defined as ImmLeaf's). This is particularly important
for X86-64, where almost all reg/imm instructions take a i64immSExt32 immediate operand,
which has a value constraint. Before this patch we ended up iseling the examples into
such amazing code as:
movabsq $7, %rax
imulq %rax, %rdi
movq %rdi, %rax
ret
now we produce:
imulq $7, %rdi, %rax
ret
This dramatically shrinks the generated code at -O0 on x86-64.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129691 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs/ProgrammersManual.html')
0 files changed, 0 insertions, 0 deletions