diff options
| -rw-r--r-- | llvm/lib/Transforms/Utils/LCSSA.cpp | 5 | ||||
| -rw-r--r-- | llvm/test/Transforms/LoopIdiom/scev-invalidation.ll | 74 |
2 files changed, 79 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Utils/LCSSA.cpp b/llvm/lib/Transforms/Utils/LCSSA.cpp index 833dea54713..38c1495fac3 100644 --- a/llvm/lib/Transforms/Utils/LCSSA.cpp +++ b/llvm/lib/Transforms/Utils/LCSSA.cpp @@ -255,6 +255,11 @@ bool LCSSA::ProcessInstruction(Instruction *Inst, if (Loop *L = LI->getLoopFor(ExitBB)) SE->forgetLoop(L); } + + // If we added a PHI, drop the cache to avoid invalidating SCEV caches. + // FIXME: This is a big hammer, can we clear the cache more selectively? + if (SE && !AddedPHIs.empty()) + SE->forgetLoop(L); // Rewrite all uses outside the loop in terms of the new PHIs we just // inserted. diff --git a/llvm/test/Transforms/LoopIdiom/scev-invalidation.ll b/llvm/test/Transforms/LoopIdiom/scev-invalidation.ll new file mode 100644 index 00000000000..a244d9a280b --- /dev/null +++ b/llvm/test/Transforms/LoopIdiom/scev-invalidation.ll @@ -0,0 +1,74 @@ +; RUN: opt -S -indvars -loop-idiom < %s +; PR14214 +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-S128" +target triple = "x86_64-unknown-linux-gnu" + +define i32 @quote_arg() nounwind { +entry: + br label %for.cond + +for.cond: ; preds = %for.inc, %entry + %backslashes.0 = phi i32 [ undef, %entry ], [ %backslashes.2, %for.inc ] + %p.0 = phi i8* [ undef, %entry ], [ %incdec.ptr3, %for.inc ] + %q.0 = phi i8* [ undef, %entry ], [ %q.2, %for.inc ] + %0 = load i8* %p.0, align 1 + switch i8 %0, label %while.cond.preheader [ + i8 0, label %for.cond4.preheader + i8 92, label %for.inc + ] + +while.cond.preheader: ; preds = %for.cond + %tobool210 = icmp eq i32 %backslashes.0, 0 + br i1 %tobool210, label %for.inc.loopexit, label %while.body.lr.ph + +while.body.lr.ph: ; preds = %while.cond.preheader + %1 = add i32 %backslashes.0, -1 + %2 = zext i32 %1 to i64 + br label %while.body + +for.cond4.preheader: ; preds = %for.cond + %tobool57 = icmp eq i32 %backslashes.0, 0 + br i1 %tobool57, label %for.end10, label %for.body6.lr.ph + +for.body6.lr.ph: ; preds = %for.cond4.preheader + br label %for.body6 + +while.body: ; preds = %while.body.lr.ph, %while.body + %q.112 = phi i8* [ %q.0, %while.body.lr.ph ], [ %incdec.ptr, %while.body ] + %backslashes.111 = phi i32 [ %backslashes.0, %while.body.lr.ph ], [ %dec, %while.body ] + %incdec.ptr = getelementptr inbounds i8* %q.112, i64 1 + store i8 92, i8* %incdec.ptr, align 1 + %dec = add nsw i32 %backslashes.111, -1 + %tobool2 = icmp eq i32 %dec, 0 + br i1 %tobool2, label %while.cond.for.inc.loopexit_crit_edge, label %while.body + +while.cond.for.inc.loopexit_crit_edge: ; preds = %while.body + %scevgep.sum = add i64 %2, 1 + %scevgep13 = getelementptr i8* %q.0, i64 %scevgep.sum + br label %for.inc.loopexit + +for.inc.loopexit: ; preds = %while.cond.for.inc.loopexit_crit_edge, %while.cond.preheader + %q.1.lcssa = phi i8* [ %scevgep13, %while.cond.for.inc.loopexit_crit_edge ], [ %q.0, %while.cond.preheader ] + br label %for.inc + +for.inc: ; preds = %for.inc.loopexit, %for.cond + %backslashes.2 = phi i32 [ %backslashes.0, %for.cond ], [ 0, %for.inc.loopexit ] + %q.2 = phi i8* [ %q.0, %for.cond ], [ %q.1.lcssa, %for.inc.loopexit ] + %incdec.ptr3 = getelementptr inbounds i8* %p.0, i64 1 + br label %for.cond + +for.body6: ; preds = %for.body6.lr.ph, %for.body6 + %q.39 = phi i8* [ %q.0, %for.body6.lr.ph ], [ %incdec.ptr7, %for.body6 ] + %backslashes.38 = phi i32 [ %backslashes.0, %for.body6.lr.ph ], [ %dec9, %for.body6 ] + %incdec.ptr7 = getelementptr inbounds i8* %q.39, i64 1 + store i8 92, i8* %incdec.ptr7, align 1 + %dec9 = add nsw i32 %backslashes.38, -1 + %tobool5 = icmp eq i32 %dec9, 0 + br i1 %tobool5, label %for.cond4.for.end10_crit_edge, label %for.body6 + +for.cond4.for.end10_crit_edge: ; preds = %for.body6 + br label %for.end10 + +for.end10: ; preds = %for.cond4.for.end10_crit_edge, %for.cond4.preheader + ret i32 undef +} |
