Better test case found in duplicate PR10570.

llvm-svn: 145484

llvm/test/Transforms/LoopStrengthReduce/2011-11-29-postincphi.ll

@@ -1,8 +1,8 @@
 ; RUN: llc < %s | FileCheck %s
 ;
 ; PR11431: handle a phi operand that is replaced by a postinc user.
-; LSR first expands %mul to %iv1 in %phi32
-; LSR then expands %iv1 in %phi32 into two decrements, one on each loop exit.
+; LSR first expands %t3 to %t2 in %phi
+; LSR then expands %t2 in %phi into two decrements, one on each loop exit.
 
 target datalayout = "e-p:64:64:64-S128-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-f128:128:128-n8:16:32:64"
 target triple = "x86_64-unknown-linux-gnu"
@@ -11,46 +11,26 @@ declare i1 @check() nounwind
 
 ; Check that LSR did something close to the behavior at the time of the bug.
 ; CHECK: @sqlite3DropTriggerPtr
-; CHECK: addq $48, %rax
-; CHECK: je
-; CHECK: addq $-48, %rax
+; CHECK: incq %rax
+; CHECK: jne
+; CHECK: decq %rax
 ; CHECK: ret
-define i64 @sqlite3DropTriggerPtr() {
-entry:
-  %cmp0 = call zeroext i1 @check()
-  br i1 %cmp0, label %"8", label %"3"
+define i64 @sqlite3DropTriggerPtr() nounwind {
+bb:
+  %cmp = call zeroext i1 @check()
+  br label %bb1
 
-"3":                                              ; preds = %entry
-  br i1 %cmp0, label %"4", label %"8"
+bb1:                                              ; preds = %bb4, %bb
+  %t0 = phi i64 [ 0, %bb ], [ %t3, %bb4 ]
+  %t2 = phi i64 [ 1, %bb ], [ %t5, %bb4 ]
+  %t3 = add nsw i64 %t0, 1
+  br i1 %cmp, label %bb4, label %bb8
 
-"4":                                              ; preds = %"3"
-  br i1 %cmp0, label %"8", label %"5.preheader"
+bb4:                                              ; preds = %bb1
+  %t5 = add nsw i64 %t2, 1
+  br i1 %cmp, label %bb1, label %bb8
 
-"5.preheader":                                    ; preds = %"4"
-  br label %"5"
-
-"5":
-  %iv0 = phi i32 [ %iv0.inc, %"6" ], [ 0, %"5.preheader" ]
-  %iv1 = phi i64 [ %iv1.inc, %"6" ], [ 48, %"5.preheader" ]
-  %iv0.inc = add nsw i32 %iv0, 1
-  %cmp = icmp eq i32 %iv0.inc, 0
-  br i1 %cmp, label %"7", label %"6"
-
-"6":
-  %iv1.inc = add i64 %iv1, 48
-  %iv1.ofs = add i64 %iv1, 40
-  %ptr8 = getelementptr inbounds i8* undef, i64 %iv1.ofs
-  %ptr32 = bitcast i8* %ptr8 to i32**
-  %v = load i32** %ptr32, align 8
-  br i1 %cmp0, label %"8", label %"5"
-
-"7":
-  %iv.inc64 = sext i32 %iv0.inc to i64
-  %mul = mul i64 %iv.inc64, 48
-  br label %"8"
-
-"8":                                              ; preds = %"7", %"5", %"4", %"3", %entry
-  %phi32 = phi i32 [ %iv0.inc, %"7" ], [ 0, %"4" ], [ 0, %"3" ], [ -1000000, %entry ], [ %iv0.inc, %"6" ]
-  %phi64 = phi i64 [ %mul, %"7" ], [ 0, %"4" ], [ 0, %"3" ], [ -48000000, %entry ], [ %iv1, %"6" ]
-  ret i64 %phi64
+bb8:                                              ; preds = %bb8, %bb4
+  %phi = phi i64 [ %t3, %bb1 ], [ %t2, %bb4 ]
+  ret i64 %phi
 }