From 3f64218ef98793b42e23fc76f6e3a7d78debb8c5 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Mon, 11 Jan 2010 06:55:24 +0000 Subject: add one more bitfield optimization, allowing clang to generate good code on PR4216: _test_bitfield: ## @test_bitfield orl $32962, %edi movl $4294941946, %eax andq %rdi, %rax ret instead of: _test_bitfield: movl $4294941696, %ecx movl %edi, %eax orl $194, %edi orl $32768, %eax andq $250, %rdi andq %rax, %rcx movq %rdi, %rax orq %rcx, %rax ret Evan is looking into the remaining andq+imm -> andl optimization. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93147 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/InstCombine/InstCombineAndOrXor.cpp | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) (limited to 'lib/Transforms') diff --git a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp index a8dd1b8..af300fc 100644 --- a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -1544,9 +1544,9 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) { } } - // ((V | N) & C1) | (V & C2) --> (V|N) & (C1|C2) - // iff (C1&C2) == 0 and (N&~C1) == 0 if ((C1->getValue() & C2->getValue()) == 0) { + // ((V | N) & C1) | (V & C2) --> (V|N) & (C1|C2) + // iff (C1&C2) == 0 and (N&~C1) == 0 if (match(A, m_Or(m_Value(V1), m_Value(V2))) && ((V1 == B && MaskedValueIsZero(V2, ~C1->getValue())) || // (V|N) (V2 == B && MaskedValueIsZero(V1, ~C1->getValue())))) // (N|V) @@ -1560,6 +1560,19 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) { return BinaryOperator::CreateAnd(B, ConstantInt::get(B->getContext(), C1->getValue()|C2->getValue())); + + // ((V|C3)&C1) | ((V|C4)&C2) --> (V|C3|C4)&(C1|C2) + // iff (C1&C2) == 0 and (C3&~C1) == 0 and (C4&~C2) == 0. + ConstantInt *C3 = 0, *C4 = 0; + if (match(A, m_Or(m_Value(V1), m_ConstantInt(C3))) && + (C3->getValue() & ~C1->getValue()) == 0 && + match(B, m_Or(m_Specific(V1), m_ConstantInt(C4))) && + (C4->getValue() & ~C2->getValue()) == 0) { + V2 = Builder->CreateOr(V1, ConstantExpr::getOr(C3, C4), "bitfield"); + return BinaryOperator::CreateAnd(V2, + ConstantInt::get(B->getContext(), + C1->getValue()|C2->getValue())); + } } } -- cgit v1.1