Jakob Stoklund Olesen 72847f3057 Reapply r155136 after fixing PR12599. ... Original commit message: Defer some shl transforms to DAGCombine. The shl instruction is used to represent multiplication by a constant power of two as well as bitwise left shifts. Some InstCombine transformations would turn an shl instruction into a bit mask operation, making it difficult for later analysis passes to recognize the constsnt multiplication. Disable those shl transformations, deferring them to DAGCombine time. An 'shl X, C' instruction is now treated mostly the same was as 'mul X, C'. These transformations are deferred: (X >>? C) << C --> X & (-1 << C) (When X >> C has multiple uses) (X >>? C1) << C2 --> X << (C2-C1) & (-1 << C2) (When C2 > C1) (X >>? C1) << C2 --> X >>? (C1-C2) & (-1 << C2) (When C1 > C2) The corresponding exact transformations are preserved, just like div-exact + mul: (X >>?,exact C) << C --> X (X >>?,exact C1) << C2 --> X << (C2-C1) (X >>?,exact C1) << C2 --> X >>?,exact (C1-C2) The disabled transformations could also prevent the instruction selector from recognizing rotate patterns in hash functions and cryptographic primitives. I have a test case for that, but it is too fragile. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155362 91177308-0d34-0410-b5e6-96231b3b80d8		2012-04-23 17:39:52 +00:00
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CodeGen	ZERO_EXTEND/SIGN_EXTEND/TRUNCATE optimization for AVX2	2012-04-22 09:39:03 +00:00
DebugInfo
ExecutionEngine	Fix incorrect call of resolveRelocation() for ARM ELF stub relocations.	2012-04-17 20:10:16 +00:00
Linker	Add a flag to the struct type finder to collect only those types which have	2012-04-21 23:59:16 +00:00
MC
Object
Support	Conflict with st_dev/st_ino identifiers under Debian GNU/Hurd	2012-04-23 16:37:23 +00:00
TableGen	Fix copy/paste-o.	2012-04-18 18:09:53 +00:00
Target	Use MVT instead of EVT through all of LowerVECTOR_SHUFFLEtoBlend and not just the switch. Saves a little bit of binary size.	2012-04-23 07:36:33 +00:00
Transforms	Reapply r155136 after fixing PR12599.	2012-04-23 17:39:52 +00:00
VMCore	Cleanup whitespace.	2012-04-23 00:23:33 +00:00
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