Chris Lattner 62fe406dc2 implement an instcombine xform that canonicalizes casts outside of and-with-constant operations. ... This fixes rdar://8808586 which observed that we used to compile: union xy { struct x { _Bool b[15]; } x; __attribute__((packed)) struct y { __attribute__((packed)) unsigned long b0to7; __attribute__((packed)) unsigned int b8to11; __attribute__((packed)) unsigned short b12to13; __attribute__((packed)) unsigned char b14; } y; }; struct x foo(union xy *xy) { return xy->x; } into: _foo: ## @foo movq (%rdi), %rax movabsq $1095216660480, %rcx ## imm = 0xFF00000000 andq %rax, %rcx movabsq $-72057594037927936, %rdx ## imm = 0xFF00000000000000 andq %rax, %rdx movzbl %al, %esi orq %rdx, %rsi movq %rax, %rdx andq $65280, %rdx ## imm = 0xFF00 orq %rsi, %rdx movq %rax, %rsi andq $16711680, %rsi ## imm = 0xFF0000 orq %rdx, %rsi movl %eax, %edx andl $-16777216, %edx ## imm = 0xFFFFFFFFFF000000 orq %rsi, %rdx orq %rcx, %rdx movabsq $280375465082880, %rcx ## imm = 0xFF0000000000 movq %rax, %rsi andq %rcx, %rsi orq %rdx, %rsi movabsq $71776119061217280, %r8 ## imm = 0xFF000000000000 andq %r8, %rax orq %rsi, %rax movzwl 12(%rdi), %edx movzbl 14(%rdi), %esi shlq $16, %rsi orl %edx, %esi movq %rsi, %r9 shlq $32, %r9 movl 8(%rdi), %edx orq %r9, %rdx andq %rdx, %rcx movzbl %sil, %esi shlq $32, %rsi orq %rcx, %rsi movl %edx, %ecx andl $-16777216, %ecx ## imm = 0xFFFFFFFFFF000000 orq %rsi, %rcx movq %rdx, %rsi andq $16711680, %rsi ## imm = 0xFF0000 orq %rcx, %rsi movq %rdx, %rcx andq $65280, %rcx ## imm = 0xFF00 orq %rsi, %rcx movzbl %dl, %esi orq %rcx, %rsi andq %r8, %rdx orq %rsi, %rdx ret We now compile this into: _foo: ## @foo ## BB#0: ## %entry movzwl 12(%rdi), %eax movzbl 14(%rdi), %ecx shlq $16, %rcx orl %eax, %ecx shlq $32, %rcx movl 8(%rdi), %edx orq %rcx, %rdx movq (%rdi), %rax ret A small improvement :-) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123520 91177308-0d34-0410-b5e6-96231b3b80d8		2011-01-15 06:32:33 +00:00
..
ADCE
ArgumentPromotion
BlockPlacement
BranchFolding
CodeExtractor
CodeGenPrepare	revert r122164, I'm going to go with a different approach.	2010-12-19 04:23:03 +00:00
ConstantMerge
ConstProp	Teach constant folding to perform conversions from constant floating	2011-01-11 01:07:24 +00:00
CorrelatedValuePropagation	Fix PR8790, another instance where unreachable code can cause instruction simplification to fail,	2010-12-15 00:55:35 +00:00
DeadArgElim
DeadStoreElimination	Fix PR8728, a miscompilation I recently introduced. When optimizing	2010-12-06 01:48:06 +00:00
EarlyCSE	Duncan deftly points out that readnone functions aren't	2011-01-03 23:38:13 +00:00
FunctionAttrs	Make ModRefBehavior a lattice. Use this to clean up AliasAnalysis	2010-11-10 01:02:18 +00:00
GlobalDCE
GlobalOpt	fix a globalopt crash on two Adobe-C++ testcases that the recent	2011-01-01 22:31:46 +00:00
GVN	Give GVN back the ability to perform simple conditional propagation on conditional branch values.	2010-12-21 23:54:34 +00:00
IndVarSimplify
Inline	relax testcase a bit.	2011-01-14 07:46:33 +00:00
InstCombine	implement an instcombine xform that canonicalizes casts outside of and-with-constant operations.	2011-01-15 06:32:33 +00:00
InstSimplify	Turn X-(X-Y) into Y. According to my auto-simplifier this is the most common	2011-01-14 15:26:10 +00:00
Internalize
IPConstantProp
JumpThreading	Teach jump threading to "look through" a select when the branch direction of a terminator depends on it.	2010-12-15 09:51:20 +00:00
LCSSA
LICM	Enhance LICM to promote alias sets whose pointers themselves are stored,	2010-12-19 05:57:25 +00:00
LoopDeletion
LoopIdiom	Teach loop-idiom to turn a loop containing a memset into a larger memset	2011-01-04 07:46:33 +00:00
LoopRotate	merge tests into one crash.ll test.	2011-01-11 07:50:07 +00:00
LoopSimplify	Fix PR8702 by not having LoopSimplify claim to preserve LCSSA form. As described	2011-01-02 13:38:21 +00:00
LoopStrengthReduce
LoopUnroll
LoopUnswitch	Factor code for testing whether replacing one value with another	2010-11-18 19:59:41 +00:00
LowerAtomic
LowerInvoke
LowerSetJmp
LowerSwitch
Mem2Reg
MemCpyOpt	revert 123144, reenabling the rest of memset formation.	2011-01-12 03:25:15 +00:00
MergeFunc
PartialSpecialize
PruneEH
Reassociate
ScalarRepl	Extend SROA to handle arrays accessed as homogeneous structs and vice versa.	2011-01-13 17:45:11 +00:00
SCCP
SimplifyCFG	SimplifyCFG: Ranges can be larger than 64 bits. Fixes Release-selfhost build.	2010-12-17 10:48:14 +00:00
SimplifyLibCalls	Revert r64460. strtol and friends cannot be marked readonly, even with	2010-12-17 01:09:43 +00:00
Sink
SRETPromotion
StripSymbols
TailCallElim
TailDup