|  | ; RUN: opt -S < %s -analyze -scalar-evolution -loop-simplify -scalar-evolution | FileCheck %s | 
|  |  | 
|  | ; Provide legal integer types. | 
|  | target datalayout = "n8:16:32:64" | 
|  |  | 
|  | @maxStat = external global i32 | 
|  |  | 
|  | ; LoopSimplify should invalidate SCEV when splitting out the | 
|  | ; inner loop. | 
|  | ; | 
|  | ; First SCEV print: | 
|  | ; CHECK-LABEL: Classifying expressions for: @test | 
|  | ; CHECK: %[[PHI:.*]] = phi i32 [ 0, %entry ], [ %{{.*}}, %if.then5 ], [ %[[PHI]], %if.end ] | 
|  | ; CHECK-LABEL: Determining loop execution counts for: @test | 
|  | ; CHECK: Loop %for.body18: Unpredictable backedge-taken count. | 
|  | ; CHECK: Loop %for.body18: max backedge-taken count is 2147483646 | 
|  | ; CHECK: Loop %for.body18: Unpredictable predicated backedge-taken count. | 
|  | ; CHECK: Loop %for.cond: <multiple exits> Unpredictable backedge-taken count. | 
|  | ; CHECK: Loop %for.cond: Unpredictable max backedge-taken count. | 
|  | ; CHECK: Loop %for.cond: Unpredictable predicated backedge-taken count. | 
|  | ; | 
|  | ; Now simplify the loop, which should cause SCEV to re-compute more precise | 
|  | ; info here in addition to having preheader PHIs. Second SCEV print: | 
|  | ; CHECK-LABEL: Classifying expressions for: @test | 
|  | ; CHECK: phi i32 [ %{{.*}}, %if.then5 ], [ 0, %entry ] | 
|  | ; CHECK-LABEL: Determining loop execution counts for: @test | 
|  | ; CHECK: Loop %for.body18: Unpredictable backedge-taken count. | 
|  | ; CHECK: Loop %for.body18: max backedge-taken count is 2147483646 | 
|  | ; CHECK: Loop %for.body18: Unpredictable predicated backedge-taken count. | 
|  | ; CHECK: Loop %for.cond: <multiple exits> Unpredictable backedge-taken count. | 
|  | ; CHECK: Loop %for.cond: max backedge-taken count is -2147483647 | 
|  | ; CHECK: Loop %for.cond: Unpredictable predicated backedge-taken count. | 
|  | ; CHECK: Loop %for.cond.outer: <multiple exits> Unpredictable backedge-taken count. | 
|  | ; CHECK: Loop %for.cond.outer: Unpredictable max backedge-taken count. | 
|  | ; CHECK: Loop %for.cond.outer: Unpredictable predicated backedge-taken count. | 
|  | define i32 @test() nounwind { | 
|  | entry: | 
|  | br label %for.cond | 
|  |  | 
|  | for.cond:                                         ; preds = %if.then5, %if.end, %entry | 
|  | %cuts.1 = phi i32 [ 0, %entry ], [ %inc, %if.then5 ], [ %cuts.1, %if.end ] | 
|  | %0 = phi i32 [ 0, %entry ], [ %add, %if.end ], [ %add, %if.then5 ] | 
|  | %add = add i32 %0, 1 | 
|  | %cmp = icmp slt i32 %0, 1 | 
|  | %tmp1 = load i32, i32* @maxStat, align 4 | 
|  | br i1 %cmp, label %for.body, label %for.cond14.preheader | 
|  |  | 
|  | for.cond14.preheader:                             ; preds = %for.cond | 
|  | %cmp1726 = icmp sgt i32 %tmp1, 0 | 
|  | br i1 %cmp1726, label %for.body18, label %return | 
|  |  | 
|  | for.body:                                         ; preds = %for.cond | 
|  | %cmp2 = icmp sgt i32 %tmp1, 100 | 
|  | br i1 %cmp2, label %return, label %if.end | 
|  |  | 
|  | if.end:                                           ; preds = %for.body | 
|  | %cmp4 = icmp sgt i32 %tmp1, -1 | 
|  | br i1 %cmp4, label %if.then5, label %for.cond | 
|  |  | 
|  | if.then5:                                         ; preds = %if.end | 
|  | call void @foo() nounwind | 
|  | %inc = add i32 %cuts.1, 1 | 
|  | br label %for.cond | 
|  |  | 
|  | for.body18:                                       ; preds = %for.body18, %for.cond14.preheader | 
|  | %i13.027 = phi i32 [ %1, %for.body18 ], [ 0, %for.cond14.preheader ] | 
|  | call void @foo() nounwind | 
|  | %1 = add nsw i32 %i13.027, 1 | 
|  | %tmp16 = load i32, i32* @maxStat, align 4 | 
|  | %cmp17 = icmp slt i32 %1, %tmp16 | 
|  | br i1 %cmp17, label %for.body18, label %return | 
|  |  | 
|  | return:                                           ; preds = %for.body18, %for.body, %for.cond14.preheader | 
|  | ret i32 0 | 
|  | } | 
|  |  | 
|  | declare void @foo() nounwind | 
|  |  | 
|  | ; Notify SCEV when removing an ExitingBlock. This only changes the | 
|  | ; backedge-taken information. | 
|  | ; | 
|  | ; First SCEV print: | 
|  | ; CHECK-LABEL: Determining loop execution counts for: @mergeExit | 
|  | ; CHECK: Loop %while.cond191: <multiple exits> Unpredictable backedge-taken count. | 
|  | ; CHECK: Loop %while.cond191: max backedge-taken count is -1 | 
|  | ; CHECK: Loop %while.cond191: Unpredictable predicated backedge-taken count. | 
|  | ; CHECK: Loop %while.cond191.outer: <multiple exits> Unpredictable backedge-taken count. | 
|  | ; CHECK: Loop %while.cond191.outer: Unpredictable max backedge-taken count. | 
|  | ; CHECK: Loop %while.cond191.outer: Unpredictable predicated backedge-taken count. | 
|  | ; | 
|  | ; After simplifying, the max backedge count is refined. | 
|  | ; Second SCEV print: | 
|  | ; CHECK-LABEL: Determining loop execution counts for: @mergeExit | 
|  | ; CHECK: Loop %while.cond191: <multiple exits> backedge-taken count is 0 | 
|  | ; CHECK: Loop %while.cond191: max backedge-taken count is 0 | 
|  | ; CHECK: Loop %while.cond191: Predicated backedge-taken count is 0 | 
|  | ; CHECK: Loop %while.cond191.outer: <multiple exits> Unpredictable backedge-taken count. | 
|  | ; CHECK: Loop %while.cond191.outer: max backedge-taken count is false | 
|  | ; CHECK: Loop %while.cond191.outer: Unpredictable predicated backedge-taken count. | 
|  | define void @mergeExit(i32 %MapAttrCount) nounwind uwtable ssp { | 
|  | entry: | 
|  | br i1 undef, label %if.then124, label %if.end126 | 
|  |  | 
|  | if.then124:                                       ; preds = %entry | 
|  | unreachable | 
|  |  | 
|  | if.end126:                                        ; preds = %entry | 
|  | br i1 undef, label %while.body.lr.ph, label %if.end591 | 
|  |  | 
|  | while.body.lr.ph:                                 ; preds = %if.end126 | 
|  | br i1 undef, label %if.end140, label %if.then137 | 
|  |  | 
|  | if.then137:                                       ; preds = %while.body.lr.ph | 
|  | unreachable | 
|  |  | 
|  | if.end140:                                        ; preds = %while.body.lr.ph | 
|  | br i1 undef, label %while.cond191.outer, label %if.then148 | 
|  |  | 
|  | if.then148:                                       ; preds = %if.end140 | 
|  | unreachable | 
|  |  | 
|  | while.cond191.outer:                              ; preds = %if.then205, %if.end140 | 
|  | br label %while.cond191 | 
|  |  | 
|  | while.cond191:                                    ; preds = %while.body197, %while.cond191.outer | 
|  | %CppIndex.0 = phi i32 [ %inc, %while.body197 ], [ undef, %while.cond191.outer ] | 
|  | br i1 undef, label %land.rhs, label %if.then216 | 
|  |  | 
|  | land.rhs:                                         ; preds = %while.cond191 | 
|  | %inc = add i32 %CppIndex.0, 1 | 
|  | %cmp196 = icmp ult i32 %inc, %MapAttrCount | 
|  | br i1 %cmp196, label %while.body197, label %if.then216 | 
|  |  | 
|  | while.body197:                                    ; preds = %land.rhs | 
|  | br i1 undef, label %if.then205, label %while.cond191 | 
|  |  | 
|  | if.then205:                                       ; preds = %while.body197 | 
|  | br label %while.cond191.outer | 
|  |  | 
|  | if.then216:                                       ; preds = %land.rhs, %while.cond191 | 
|  | br i1 undef, label %if.else, label %if.then221 | 
|  |  | 
|  | if.then221:                                       ; preds = %if.then216 | 
|  | unreachable | 
|  |  | 
|  | if.else:                                          ; preds = %if.then216 | 
|  | br i1 undef, label %if.then266, label %if.end340 | 
|  |  | 
|  | if.then266:                                       ; preds = %if.else | 
|  | switch i32 undef, label %if.else329 [ | 
|  | i32 17, label %if.then285 | 
|  | i32 19, label %if.then285 | 
|  | i32 18, label %if.then285 | 
|  | i32 15, label %if.then285 | 
|  | ] | 
|  |  | 
|  | if.then285:                                       ; preds = %if.then266, %if.then266, %if.then266, %if.then266 | 
|  | br i1 undef, label %if.then317, label %if.else324 | 
|  |  | 
|  | if.then317:                                       ; preds = %if.then285 | 
|  | br label %if.end340 | 
|  |  | 
|  | if.else324:                                       ; preds = %if.then285 | 
|  | unreachable | 
|  |  | 
|  | if.else329:                                       ; preds = %if.then266 | 
|  | unreachable | 
|  |  | 
|  | if.end340:                                        ; preds = %if.then317, %if.else | 
|  | unreachable | 
|  |  | 
|  | if.end591:                                        ; preds = %if.end126 | 
|  | br i1 undef, label %cond.end, label %cond.false | 
|  |  | 
|  | cond.false:                                       ; preds = %if.end591 | 
|  | unreachable | 
|  |  | 
|  | cond.end:                                         ; preds = %if.end591 | 
|  | ret void | 
|  | } |