When attempting to sign-extend an addrec by interpreting

the step value as unsigned, the start value and the addrec
itself still need to be treated as signed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77078 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 49af579366297a6161e36dc7100bd3774365de92..6592e0d0778b15bc4813704961fd3462546076bd 100644 (file)
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -923,10 +923,10 @@ const SCEV *ScalarEvolution::getSignExtendExpr(const SCEV *Op,
                        getTruncateOrZeroExtend(Step, Start->getType()));
           Add = getAddExpr(Start, UMul);
           OperandExtendedAdd =
-            getAddExpr(getZeroExtendExpr(Start, WideTy),
+            getAddExpr(getSignExtendExpr(Start, WideTy),
                        getMulExpr(getZeroExtendExpr(CastedMaxBECount, WideTy),
                                   getZeroExtendExpr(Step, WideTy)));
-          if (getZeroExtendExpr(Add, WideTy) == OperandExtendedAdd)
+          if (getSignExtendExpr(Add, WideTy) == OperandExtendedAdd)
             // Return the expression with the addrec on the outside.
             return getAddRecExpr(getSignExtendExpr(Start, Ty),
                                  getZeroExtendExpr(Step, Ty),

diff --git a/test/Analysis/ScalarEvolution/sext-iv-2.ll b/test/Analysis/ScalarEvolution/sext-iv-2.ll
new file mode 100644 (file)
index 0000000..10bcc47
--- /dev/null
+++ b/test/Analysis/ScalarEvolution/sext-iv-2.ll
@@ -0,0 +1,74 @@
+; RUN: llvm-as < %s | opt -analyze -scalar-evolution -disable-output | FileCheck %s
+
+; CHECK: %tmp3 = sext i8 %tmp2 to i32
+; CHECK: -->  (sext i8 {0,+,1}<bb1> to i32)   Exits: -1
+; CHECK: %tmp4 = mul i32 %tmp3, %i.02
+; CHECK: -->  ((sext i8 {0,+,1}<bb1> to i32) * {0,+,1}<bb>)   Exits: {0,+,-1}<bb>
+
+; These sexts are not foldable.
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64"
+
+@table = common global [32 x [256 x i32]] zeroinitializer, align 32            ; <[32 x [256 x i32]]*> [#uses=2]
+
+define i32 @main() nounwind {
+entry:
+       br i1 false, label %bb5, label %bb.nph3
+
+bb.nph3:               ; preds = %entry
+       br label %bb
+
+bb:            ; preds = %bb4, %bb.nph3
+       %i.02 = phi i32 [ %tmp10, %bb4 ], [ 0, %bb.nph3 ]               ; <i32> [#uses=3]
+       br i1 false, label %bb3, label %bb.nph
+
+bb.nph:                ; preds = %bb
+       br label %bb1
+
+bb1:           ; preds = %bb2, %bb.nph
+       %j.01 = phi i32 [ %tmp8, %bb2 ], [ 0, %bb.nph ]         ; <i32> [#uses=3]
+       %tmp2 = trunc i32 %j.01 to i8           ; <i8> [#uses=1]
+       %tmp3 = sext i8 %tmp2 to i32            ; <i32> [#uses=1]
+       %tmp4 = mul i32 %tmp3, %i.02            ; <i32> [#uses=1]
+       %tmp5 = sext i32 %i.02 to i64           ; <i64> [#uses=1]
+       %tmp6 = sext i32 %j.01 to i64           ; <i64> [#uses=1]
+       %tmp7 = getelementptr [32 x [256 x i32]]* @table, i64 0, i64 %tmp5, i64 %tmp6           ; <i32*> [#uses=1]
+       store i32 %tmp4, i32* %tmp7, align 4
+       %tmp8 = add i32 %j.01, 1                ; <i32> [#uses=2]
+       br label %bb2
+
+bb2:           ; preds = %bb1
+       %phitmp1 = icmp sgt i32 %tmp8, 255              ; <i1> [#uses=1]
+       br i1 %phitmp1, label %bb2.bb3_crit_edge, label %bb1
+
+bb2.bb3_crit_edge:             ; preds = %bb2
+       br label %bb3
+
+bb3:           ; preds = %bb2.bb3_crit_edge, %bb
+       %tmp10 = add i32 %i.02, 1               ; <i32> [#uses=2]
+       br label %bb4
+
+bb4:           ; preds = %bb3
+       %phitmp = icmp sgt i32 %tmp10, 31               ; <i1> [#uses=1]
+       br i1 %phitmp, label %bb4.bb5_crit_edge, label %bb
+
+bb4.bb5_crit_edge:             ; preds = %bb4
+       br label %bb5
+
+bb5:           ; preds = %bb4.bb5_crit_edge, %entry
+       %tmp12 = load i32* getelementptr ([32 x [256 x i32]]* @table, i64 0, i64 9, i64 132), align 16          ; <i32> [#uses=1]
+       %tmp13 = icmp eq i32 %tmp12, -1116              ; <i1> [#uses=1]
+       br i1 %tmp13, label %bb7, label %bb6
+
+bb6:           ; preds = %bb5
+       call void @abort() noreturn nounwind
+       unreachable
+
+bb7:           ; preds = %bb5
+       br label %return
+
+return:                ; preds = %bb7
+       ret i32 0
+}
+
+declare void @abort() noreturn nounwind