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| author | Nadav Rotem <nrotem@apple.com> | 2013-11-10 04:13:31 +0000 |
|---|---|---|
| committer | Nadav Rotem <nrotem@apple.com> | 2013-11-10 04:13:31 +0000 |
| commit | 30150a128c7b2488225331417153ccec75bac65c (patch) | |
| tree | 9dda8d3f33330407319195c979403e9202b568e2 | |
| parent | 20f1fe5c50c1a8ea69e635b4928c7f46e10c8cac (diff) | |
| download | external_llvm-30150a128c7b2488225331417153ccec75bac65c.zip external_llvm-30150a128c7b2488225331417153ccec75bac65c.tar.gz external_llvm-30150a128c7b2488225331417153ccec75bac65c.tar.bz2 | |
SimplifyCFG has a heuristics for out-of-order processors that decides when it is worthwhile to merge branches. It tries to estimate if the operands of the instruction that we want to hoist are ready. This commit marks function arguments as 'ready' because they require no calculation. This boosts libquantum and a few other workloads from the testsuite.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194346 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Transforms/Utils/SimplifyCFG.cpp | 2 | ||||
| -rw-r--r-- | test/Transforms/SimplifyCFG/common-dest-folding.ll | 28 |
2 files changed, 29 insertions, 1 deletions
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp index 1398697..d36d9dc 100644 --- a/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/lib/Transforms/Utils/SimplifyCFG.cpp @@ -2096,7 +2096,7 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI) { for (Instruction::op_iterator OI = BonusInst->op_begin(), OE = BonusInst->op_end(); OI != OE; ++OI) { Value *V = *OI; - if (!isa<Constant>(V)) + if (!isa<Constant>(V) && !isa<Argument>(V)) UsedValues.insert(V); } diff --git a/test/Transforms/SimplifyCFG/common-dest-folding.ll b/test/Transforms/SimplifyCFG/common-dest-folding.ll new file mode 100644 index 0000000..10fb7d4 --- /dev/null +++ b/test/Transforms/SimplifyCFG/common-dest-folding.ll @@ -0,0 +1,28 @@ +; RUN: opt < %s -simplifycfg -S | FileCheck %s + +;CHECK: @foo +;CHECK: and i32 %c1, %k +;CHECK: icmp eq i32 +;CHECK: and i32 %c2, %k +;CHECK: icmp eq i32 +;CHECK: or i1 +;CHECK: ret +define i32 @foo(i32 %k, i32 %c1, i32 %c2) { + %1 = and i32 %c1, %k + %2 = icmp eq i32 %1, 0 + br i1 %2, label %8, label %3 + +; <label>:3 ; preds = %0 + %4 = and i32 %c2, %k + %5 = icmp eq i32 %4, 0 + br i1 %5, label %8, label %6 + +; <label>:6 ; preds = %3 + %7 = tail call i32 (...)* @bar() nounwind + br label %8 + +; <label>:8 ; preds = %3, %0, %6 + ret i32 undef +} + +declare i32 @bar(...) |