Chris Lattner 0a85420409 Extend CanEvaluateZExtd to handle and/or/xor more aggressively in the ... BitsToClear case. This allows it to promote expressions which have an and/or/xor after the lshr, promoting cases like test2 (from PR4216) and test3 (random extample extracted from a spec benchmark). clang now compiles the code in PR4216 into: _test_bitfield: ## @test_bitfield movl %edi, %eax orl $194, %eax movl $4294902010, %ecx andq %rax, %rcx orl $32768, %edi andq $39936, %rdi movq %rdi, %rax orq %rcx, %rax ret instead of: _test_bitfield: ## @test_bitfield movl %edi, %eax orl $194, %eax movl $4294902010, %ecx andq %rax, %rcx shrl $8, %edi orl $128, %edi shlq $8, %rdi andq $39936, %rdi movq %rdi, %rax orq %rcx, %rax ret which is still not great, but is progress. llvm-svn: 93145		2010-01-11 04:05:13 +00:00
clang	add a TODO for a perf improvement in LexIdentifier.	2010-01-11 02:38:50 +00:00
compiler-rt	Use __USER_LABEL_PREFIX__ so that we don't add a _ prefix on ELF.	2009-11-09 14:27:04 +00:00
llvm	Extend CanEvaluateZExtd to handle and/or/xor more aggressively in the	2010-01-11 04:05:13 +00:00