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
..
CMakeLists.txt
InstCombine.h	Move getOrEnforceKnownAlignment out of instcombine into Transforms/Utils.	2010-12-25 20:37:57 +00:00
InstCombineAddSub.cpp	one more instcombine variant that is needed to work with future changes,	2011-01-15 05:50:18 +00:00
InstCombineAndOrXor.cpp	reduce indentation	2011-01-15 05:40:29 +00:00
InstCombineCalls.cpp	Teach instcombine about the rest of the SSE and SSE2 conversion	2011-01-10 07:19:37 +00:00
InstCombineCasts.cpp	implement an instcombine xform that canonicalizes casts outside of and-with-constant operations.	2011-01-15 06:32:33 +00:00
InstCombineCompares.cpp	fix typo	2011-01-15 05:42:47 +00:00
InstCombineLoadStoreAlloca.cpp	Move getOrEnforceKnownAlignment out of instcombine into Transforms/Utils.	2010-12-25 20:37:57 +00:00
InstCombineMulDivRem.cpp	Add a generic expansion transform: A op (B op' C) -> (A op B) op' (A op C)	2010-12-22 13:36:08 +00:00
InstCombinePHI.cpp
InstCombineSelect.cpp	Instcombine: Fix pattern where the sext did not dominate the icmp using it	2011-01-09 16:00:11 +00:00
InstCombineShifts.cpp	Move some shift transforms out of instcombine and into InstructionSimplify.	2011-01-14 00:37:45 +00:00
InstCombineSimplifyDemanded.cpp
InstCombineVectorOps.cpp
InstCombineWorklist.h
InstructionCombining.cpp	Add a generic expansion transform: A op (B op' C) -> (A op B) op' (A op C)	2010-12-22 13:36:08 +00:00
Makefile