From bb5d92741b2835eff25e4524bc6a5b0fb4fda855 Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Thu, 15 Jul 2010 23:38:13 +0000 Subject: [PATCH] Fix the order that SCEVExpander considers add operands in so that it doesn't miss an opportunity to form a GEP, regardless of the relative loop depths of the operands. This fixes rdar://8197217. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108475 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/ScalarEvolutionExpander.cpp | 16 +++++++-- test/Transforms/IndVarSimplify/uglygep.ll | 40 +++++++++++++++++++++++ 2 files changed, 54 insertions(+), 2 deletions(-) create mode 100644 test/Transforms/IndVarSimplify/uglygep.ll diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp index d4a4b26e25e..0f3e33fe531 100644 --- a/lib/Analysis/ScalarEvolutionExpander.cpp +++ b/lib/Analysis/ScalarEvolutionExpander.cpp @@ -647,6 +647,11 @@ public: bool operator()(std::pair LHS, std::pair RHS) const { + // Keep pointer operands sorted at the end. + if (LHS.second->getType()->isPointerTy() != + RHS.second->getType()->isPointerTy()) + return LHS.second->getType()->isPointerTy(); + // Compare loops with PickMostRelevantLoop. if (LHS.first != RHS.first) return PickMostRelevantLoop(LHS.first, RHS.first, DT) != LHS.first; @@ -699,8 +704,15 @@ Value *SCEVExpander::visitAddExpr(const SCEVAddExpr *S) { // The running sum expression is a pointer. Try to form a getelementptr // at this level with that as the base. SmallVector NewOps; - for (; I != E && I->first == CurLoop; ++I) - NewOps.push_back(I->second); + for (; I != E && I->first == CurLoop; ++I) { + // If the operand is SCEVUnknown and not instructions, peek through + // it, to enable more of it to be folded into the GEP. + const SCEV *X = I->second; + if (const SCEVUnknown *U = dyn_cast(X)) + if (!isa(U->getValue())) + X = SE.getSCEV(U->getValue()); + NewOps.push_back(X); + } Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, Sum); } else if (const PointerType *PTy = dyn_cast(Op->getType())) { // The running sum is an integer, and there's a pointer at this level. diff --git a/test/Transforms/IndVarSimplify/uglygep.ll b/test/Transforms/IndVarSimplify/uglygep.ll new file mode 100644 index 00000000000..469b7c0ffd8 --- /dev/null +++ b/test/Transforms/IndVarSimplify/uglygep.ll @@ -0,0 +1,40 @@ +; RUN: opt -indvars -S | not grep uglygep +; rdar://8197217 + +; Indvars should be able to emit a clean GEP here, not an uglygep. + +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64" +target triple = "x86_64-apple-darwin11.0" + +@numf2s = external global i32 ; [#uses=1] +@numf1s = external global i32 ; [#uses=1] +@tds = external global double** ; [#uses=1] + +define void @init_td(i32 %tmp7) nounwind { +entry: + br label %bb4 + +bb4: ; preds = %bb3, %entry + %i.0 = phi i32 [ 0, %entry ], [ %tmp9, %bb3 ] ; [#uses=3] + br label %bb + +bb: ; preds = %bb4 + br label %bb2 + +bb2: ; preds = %bb1, %bb + %j.0 = phi i32 [ 0, %bb ], [ %tmp6, %bb1 ] ; [#uses=3] + %tmp8 = icmp slt i32 %j.0, %tmp7 ; [#uses=1] + br i1 %tmp8, label %bb1, label %bb3 + +bb1: ; preds = %bb2 + %tmp = load double*** @tds, align 8 ; [#uses=1] + %tmp1 = sext i32 %i.0 to i64 ; [#uses=1] + %tmp2 = getelementptr inbounds double** %tmp, i64 %tmp1 ; [#uses=1] + %tmp3 = load double** %tmp2, align 1 ; [#uses=1] + %tmp6 = add nsw i32 %j.0, 1 ; [#uses=1] + br label %bb2 + +bb3: ; preds = %bb2 + %tmp9 = add nsw i32 %i.0, 1 ; [#uses=1] + br label %bb4 +} -- 2.34.1