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| author | Chris Lattner <sabre@nondot.org> | 2010-12-13 07:00:06 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2010-12-13 07:00:06 +0000 |
| commit | daa02ab70c7619cc22131c75c62390cf3f5f8891 (patch) | |
| tree | bb773715018c381e3ab61c4bd3a1123c3c1e45fd /lib/CodeGen/MachineLoopInfo.cpp | |
| parent | 021c9d3bd41bc446ef0860c05a073e32afa5e20f (diff) | |
Make simplifycfg reprocess newly formed "br (cond1 | cond2)" conditions
when simplifying, allowing them to be eagerly turned into switches. This
is the last step required to get "Example 7" from this blog post:
http://blog.regehr.org/archives/320
On X86, we now generate this machine code, which (to my eye) seems better
than the ICC generated code:
_crud: ## @crud
## BB#0: ## %entry
cmpb $33, %dil
jb LBB0_4
## BB#1: ## %switch.early.test
addb $-34, %dil
cmpb $58, %dil
ja LBB0_3
## BB#2: ## %switch.early.test
movzbl %dil, %eax
movabsq $288230376537592865, %rcx ## imm = 0x400000017001421
btq %rax, %rcx
jb LBB0_4
LBB0_3: ## %lor.rhs
xorl %eax, %eax
ret
LBB0_4: ## %lor.end
movl $1, %eax
ret
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121690 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/MachineLoopInfo.cpp')
0 files changed, 0 insertions, 0 deletions