[llvm-commits] [llvm] r77078 - in /llvm/trunk: lib/Analysis/ScalarEvolution.cpp test/Analysis/ScalarEvolution/sext-iv-2.ll

[Dan Gohman]

Author: djg
Date: Sat Jul 25 11:03:30 2009
New Revision: 77078

URL: http://llvm.org/viewvc/llvm-project?rev=77078&view=rev
Log:
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.

Added:
    llvm/trunk/test/Analysis/ScalarEvolution/sext-iv-2.ll
Modified:
    llvm/trunk/lib/Analysis/ScalarEvolution.cpp

Modified: llvm/trunk/lib/Analysis/ScalarEvolution.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolution.cpp?rev=77078&r1=77077&r2=77078&view=diff

==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolution.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolution.cpp Sat Jul 25 11:03:30 2009
@@ -923,10 +923,10 @@
                        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),

Added: llvm/trunk/test/Analysis/ScalarEvolution/sext-iv-2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/ScalarEvolution/sext-iv-2.ll?rev=77078&view=auto

==============================================================================
--- llvm/trunk/test/Analysis/ScalarEvolution/sext-iv-2.ll (added)
+++ llvm/trunk/test/Analysis/ScalarEvolution/sext-iv-2.ll Sat Jul 25 11:03:30 2009
@@ -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"
+
+ at 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