From: Nick Lewycky <nicholas@mxc.ca>
Date: Sun, 23 Jan 2011 20:06:05 +0000 (+0000)
Subject: Simplify some code with no functionality change. Make the test a lot more
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=76167af9b1968b2824fcb76db0bc571f422035b4;p=oota-llvm.git

Simplify some code with no functionality change. Make the test a lot more
robust against smarter optimizations, using the power of FileCheck.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124081 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 0f2afb2096c..e3fcb8428e8 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -904,15 +904,11 @@ const SCEV *ScalarEvolution::getZeroExtendExpr(const SCEV *Op,
     // so, we should be able to simplify this further.
     const SCEV *X = ST->getOperand();
     ConstantRange CR = getUnsignedRange(X);
-    unsigned OrigBits = CR.getBitWidth();
     unsigned TruncBits = getTypeSizeInBits(ST->getType());
     unsigned NewBits = getTypeSizeInBits(Ty);
     if (CR.truncate(TruncBits).zeroExtend(NewBits).contains(
-            CR.zextOrTrunc(NewBits))) {
-      if (NewBits > OrigBits) return getZeroExtendExpr(X, Ty);
-      if (NewBits < OrigBits) return getTruncateExpr(X, Ty);
-      return X;
-    }
+            CR.zextOrTrunc(NewBits)))
+      return getTruncateOrZeroExtend(X, Ty);
   }
 
   // If the input value is a chrec scev, and we can prove that the value
@@ -1062,15 +1058,11 @@ const SCEV *ScalarEvolution::getSignExtendExpr(const SCEV *Op,
     // so, we should be able to simplify this further.
     const SCEV *X = ST->getOperand();
     ConstantRange CR = getSignedRange(X);
-    unsigned OrigBits = CR.getBitWidth();
     unsigned TruncBits = getTypeSizeInBits(ST->getType());
     unsigned NewBits = getTypeSizeInBits(Ty);
     if (CR.truncate(TruncBits).signExtend(NewBits).contains(
-            CR.sextOrTrunc(NewBits))) {
-      if (NewBits > OrigBits) return getSignExtendExpr(X, Ty);
-      if (NewBits < OrigBits) return getTruncateExpr(X, Ty);
-      return X;
-    }
+            CR.sextOrTrunc(NewBits)))
+      return getTruncateOrSignExtend(X, Ty);
   }
 
   // If the input value is a chrec scev, and we can prove that the value
diff --git a/test/Analysis/ScalarEvolution/fold.ll b/test/Analysis/ScalarEvolution/fold.ll
index 90012a38ac5..4e2adf187e8 100644
--- a/test/Analysis/ScalarEvolution/fold.ll
+++ b/test/Analysis/ScalarEvolution/fold.ll
@@ -23,36 +23,40 @@ define i8 @test3(i8 %x) {
   ret i8 %C
 }
 
-define void @test4(i32 %x) {
+define void @test4(i32 %x, i32 %y) {
 entry:
-  %0 = icmp sge i32 %x, 0
-  br i1 %0, label %loop, label %exit
+  %Y = and i32 %y, 3
+  br label %loop
 loop:
   %A = phi i32 [0, %entry], [%I, %loop]
-  %rand = icmp sgt i32 %A, 10
-  %Z = select i1 %rand, i32 %A, i32 10
-  %B = trunc i32 %Z to i16
+  %rand1 = icmp sgt i32 %A, %Y
+  %Z1 = select i1 %rand1, i32 %A, i32 %Y
+  %rand2 = icmp ugt i32 %A, %Z1
+  %Z2 = select i1 %rand2, i32 %A, i32 %Z1
+; CHECK: %Z2 =
+; CHECK-NEXT: -->  ([[EXPR:.*]]){{ +}}Exits: 20
+  %B = trunc i32 %Z2 to i16
   %C = sext i16 %B to i30
 ; CHECK: %C =
-; CHECK-NEXT: (trunc i32 (10 smax {0,+,1}<%loop>) to i30)
+; CHECK-NEXT: (trunc i32 ([[EXPR]]) to i30)
   %D = sext i16 %B to i32
 ; CHECK: %D =
-; CHECK-NEXT: (10 smax {0,+,1}<%loop>)
+; CHECK-NEXT: ([[EXPR]])
   %E = sext i16 %B to i34
 ; CHECK: %E =
-; CHECK-NEXT: (zext i32 (10 smax {0,+,1}<%loop>) to i34)
+; CHECK-NEXT: (zext i32 ([[EXPR]]) to i34)
   %F = zext i16 %B to i30
 ; CHECK: %F =
-; CHECK-NEXT: (trunc i32 (10 smax {0,+,1}<%loop>) to i30
+; CHECK-NEXT: (trunc i32 ([[EXPR]]) to i30
   %G = zext i16 %B to i32
 ; CHECK: %G =
-; CHECK-NEXT: (10 smax {0,+,1}<%loop>)
+; CHECK-NEXT: ([[EXPR]])
   %H = zext i16 %B to i34
 ; CHECK: %H =
-; CHECK-NEXT: (zext i32 (10 smax {0,+,1}<%loop>) to i34)
+; CHECK-NEXT: (zext i32 ([[EXPR]]) to i34)
   %I = add i32 %A, 1
-  %1 = icmp ne i32 %A, 20
-  br i1 %1, label %loop, label %exit
+  %0 = icmp ne i32 %A, 20
+  br i1 %0, label %loop, label %exit
 exit:
   ret void
-}
\ No newline at end of file
+}