diff options
| -rw-r--r-- | lib/Transforms/Scalar/LoopStrengthReduce.cpp | 74 | ||||
| -rw-r--r-- | test/CodeGen/X86/2008-07-07-DanglingDeadInsts.ll | 99 |
2 files changed, 136 insertions, 37 deletions
diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp index 7a372024c9..ccb25f05a6 100644 --- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp +++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp @@ -1737,6 +1737,7 @@ void LoopStrengthReduce::OptimizeIndvars(Loop *L) { // live ranges for the IV correctly. CondUse->Offset = SE->getMinusSCEV(CondUse->Offset, *CondStride); CondUse->isUseOfPostIncrementedValue = true; + Changed = true; } bool LoopStrengthReduce::runOnLoop(Loop *L, LPPassManager &LPM) { @@ -1754,49 +1755,48 @@ bool LoopStrengthReduce::runOnLoop(Loop *L, LPPassManager &LPM) { for (BasicBlock::iterator I = L->getHeader()->begin(); isa<PHINode>(I); ++I) AddUsersIfInteresting(I, L, Processed); - // If we have nothing to do, return. - if (IVUsesByStride.empty()) return false; + if (!IVUsesByStride.empty()) { + // Optimize induction variables. Some indvar uses can be transformed to use + // strides that will be needed for other purposes. A common example of this + // is the exit test for the loop, which can often be rewritten to use the + // computation of some other indvar to decide when to terminate the loop. + OptimizeIndvars(L); - // Optimize induction variables. Some indvar uses can be transformed to use - // strides that will be needed for other purposes. A common example of this - // is the exit test for the loop, which can often be rewritten to use the - // computation of some other indvar to decide when to terminate the loop. - OptimizeIndvars(L); + // FIXME: We can widen subreg IV's here for RISC targets. e.g. instead of + // doing computation in byte values, promote to 32-bit values if safe. + // FIXME: Attempt to reuse values across multiple IV's. In particular, we + // could have something like "for(i) { foo(i*8); bar(i*16) }", which should + // be codegened as "for (j = 0;; j+=8) { foo(j); bar(j+j); }" on X86/PPC. + // Need to be careful that IV's are all the same type. Only works for + // intptr_t indvars. - // FIXME: We can widen subreg IV's here for RISC targets. e.g. instead of - // doing computation in byte values, promote to 32-bit values if safe. - - // FIXME: Attempt to reuse values across multiple IV's. In particular, we - // could have something like "for(i) { foo(i*8); bar(i*16) }", which should be - // codegened as "for (j = 0;; j+=8) { foo(j); bar(j+j); }" on X86/PPC. Need - // to be careful that IV's are all the same type. Only works for intptr_t - // indvars. - - // If we only have one stride, we can more aggressively eliminate some things. - bool HasOneStride = IVUsesByStride.size() == 1; + // If we only have one stride, we can more aggressively eliminate some + // things. + bool HasOneStride = IVUsesByStride.size() == 1; #ifndef NDEBUG - DOUT << "\nLSR on "; - DEBUG(L->dump()); + DOUT << "\nLSR on "; + DEBUG(L->dump()); #endif - // IVsByStride keeps IVs for one particular loop. - assert(IVsByStride.empty() && "Stale entries in IVsByStride?"); - - // Sort the StrideOrder so we process larger strides first. - std::stable_sort(StrideOrder.begin(), StrideOrder.end(), StrideCompare()); - - // Note: this processes each stride/type pair individually. All users passed - // into StrengthReduceStridedIVUsers have the same type AND stride. Also, - // note that we iterate over IVUsesByStride indirectly by using StrideOrder. - // This extra layer of indirection makes the ordering of strides deterministic - // - not dependent on map order. - for (unsigned Stride = 0, e = StrideOrder.size(); Stride != e; ++Stride) { - std::map<SCEVHandle, IVUsersOfOneStride>::iterator SI = - IVUsesByStride.find(StrideOrder[Stride]); - assert(SI != IVUsesByStride.end() && "Stride doesn't exist!"); - StrengthReduceStridedIVUsers(SI->first, SI->second, L, HasOneStride); + // IVsByStride keeps IVs for one particular loop. + assert(IVsByStride.empty() && "Stale entries in IVsByStride?"); + + // Sort the StrideOrder so we process larger strides first. + std::stable_sort(StrideOrder.begin(), StrideOrder.end(), StrideCompare()); + + // Note: this processes each stride/type pair individually. All users + // passed into StrengthReduceStridedIVUsers have the same type AND stride. + // Also, note that we iterate over IVUsesByStride indirectly by using + // StrideOrder. This extra layer of indirection makes the ordering of + // strides deterministic - not dependent on map order. + for (unsigned Stride = 0, e = StrideOrder.size(); Stride != e; ++Stride) { + std::map<SCEVHandle, IVUsersOfOneStride>::iterator SI = + IVUsesByStride.find(StrideOrder[Stride]); + assert(SI != IVUsesByStride.end() && "Stride doesn't exist!"); + StrengthReduceStridedIVUsers(SI->first, SI->second, L, HasOneStride); + } } // We're done analyzing this loop; release all the state we built up for it. @@ -1839,5 +1839,5 @@ bool LoopStrengthReduce::runOnLoop(Loop *L, LPPassManager &LPM) { DeleteTriviallyDeadInstructions(DeadInsts); } - return false; + return Changed; } diff --git a/test/CodeGen/X86/2008-07-07-DanglingDeadInsts.ll b/test/CodeGen/X86/2008-07-07-DanglingDeadInsts.ll new file mode 100644 index 0000000000..3586f87776 --- /dev/null +++ b/test/CodeGen/X86/2008-07-07-DanglingDeadInsts.ll @@ -0,0 +1,99 @@ +; RUN: llvm-as < %s | llc -mtriple=i386-apple-darwin9 + + %struct.ogg_stream_state = type { i8*, i32, i32, i32, i32*, i64*, i32, i32, i32, i32, [282 x i8], i32, i32, i32, i32, i32, i64, i64 } + %struct.res_state = type { i32, i32, i32, i32, float*, float*, i32, i32 } + %struct.vorbis_comment = type { i8**, i32*, i32, i8* } + +declare i32 @strlen(i8*) nounwind readonly + +define i32 @res_init(%struct.res_state* %state, i32 %channels, i32 %outfreq, i32 %infreq, i32 %op1, ...) nounwind { +entry: + br i1 false, label %bb95, label %bb + +bb: ; preds = %entry + br i1 false, label %bb95, label %bb24 + +bb24: ; preds = %bb + br i1 false, label %bb40.preheader, label %bb26 + +bb26: ; preds = %bb24 + ret i32 -1 + +bb40.preheader: ; preds = %bb24 + br i1 false, label %bb39, label %bb49.outer + +bb39: ; preds = %bb39, %bb40.preheader + shl i32 0, 1 ; <i32>:0 [#uses=0] + br i1 false, label %bb39, label %bb49.outer + +bb49.outer: ; preds = %bb39, %bb40.preheader + getelementptr %struct.res_state* %state, i32 0, i32 3 ; <i32*>:1 [#uses=0] + getelementptr %struct.res_state* %state, i32 0, i32 7 ; <i32*>:2 [#uses=0] + %base10.1 = select i1 false, float* null, float* null ; <float*> [#uses=1] + br label %bb74 + +bb69: ; preds = %bb74 + br label %bb71 + +bb71: ; preds = %bb74, %bb69 + store float 0.000000e+00, float* null, align 4 + add i32 0, 1 ; <i32>:3 [#uses=1] + %indvar.next137 = add i32 %indvar136, 1 ; <i32> [#uses=1] + br i1 false, label %bb74, label %bb73 + +bb73: ; preds = %bb71 + %.rec = add i32 %base10.2.ph.rec, 1 ; <i32> [#uses=2] + getelementptr float* %base10.1, i32 %.rec ; <float*>:4 [#uses=1] + br label %bb74 + +bb74: ; preds = %bb73, %bb71, %bb49.outer + %N13.1.ph = phi i32 [ 0, %bb49.outer ], [ 0, %bb73 ], [ %N13.1.ph, %bb71 ] ; <i32> [#uses=1] + %dest12.2.ph = phi float* [ null, %bb49.outer ], [ %4, %bb73 ], [ %dest12.2.ph, %bb71 ] ; <float*> [#uses=1] + %x8.0.ph = phi i32 [ 0, %bb49.outer ], [ %3, %bb73 ], [ %x8.0.ph, %bb71 ] ; <i32> [#uses=1] + %base10.2.ph.rec = phi i32 [ 0, %bb49.outer ], [ %.rec, %bb73 ], [ %base10.2.ph.rec, %bb71 ] ; <i32> [#uses=2] + %indvar136 = phi i32 [ %indvar.next137, %bb71 ], [ 0, %bb73 ], [ 0, %bb49.outer ] ; <i32> [#uses=1] + br i1 false, label %bb71, label %bb69 + +bb95: ; preds = %bb, %entry + ret i32 -1 +} + +define i32 @read_resampled(i8* %d, float** %buffer, i32 %samples) nounwind { +entry: + br i1 false, label %bb17.preheader, label %bb30 + +bb17.preheader: ; preds = %entry + load i32* null, align 4 ; <i32>:0 [#uses=0] + br label %bb16 + +bb16: ; preds = %bb16, %bb17.preheader + %i1.036 = phi i32 [ 0, %bb17.preheader ], [ %1, %bb16 ] ; <i32> [#uses=1] + add i32 %i1.036, 1 ; <i32>:1 [#uses=2] + icmp ult i32 %1, 0 ; <i1>:2 [#uses=0] + br label %bb16 + +bb30: ; preds = %entry + ret i32 0 +} + +define i32 @ogg_stream_reset_serialno(%struct.ogg_stream_state* %os, i32 %serialno) nounwind { +entry: + unreachable +} + +define void @vorbis_lsp_to_curve(float* %curve, i32* %map, i32 %n, i32 %ln, float* %lsp, i32 %m, float %amp, float %ampoffset) nounwind { +entry: + unreachable +} + +define i32 @vorbis_comment_query_count(%struct.vorbis_comment* %vc, i8* %tag) nounwind { +entry: + %strlen = call i32 @strlen( i8* null ) ; <i32> [#uses=1] + %endptr = getelementptr i8* null, i32 %strlen ; <i8*> [#uses=0] + unreachable +} + +define fastcc i32 @push(%struct.res_state* %state, float* %pool, i32* %poolfill, i32* %offset, float* %dest, i32 %dststep, float* %source, i32 %srcstep, i32 %srclen) nounwind { +entry: + unreachable +} |