[PATCH] D33815: [ConstantRange] Implement getSignedMin/Max in a less complicated way

[Craig Topper via Phabricator via llvm-commits]

craig.topper created this revision.

As far as I can tell we should be able to implement these almost the same way we do unsigned, but using signed comparisons and checks for min signed value instead of min unsigned value.


https://reviews.llvm.org/D33815

Files:
  lib/IR/ConstantRange.cpp


Index: lib/IR/ConstantRange.cpp
===================================================================
--- lib/IR/ConstantRange.cpp
+++ lib/IR/ConstantRange.cpp
@@ -284,27 +284,14 @@
 }
 
 APInt ConstantRange::getSignedMax() const {
-  if (!isWrappedSet()) {
-    APInt UpperMinusOne = getUpper() - 1;
-    if (getLower().sle(UpperMinusOne))
-      return UpperMinusOne;
-    return APInt::getSignedMaxValue(getBitWidth());
-  }
-  if (getLower().isNegative() == getUpper().isNegative())
+  if (isFullSet() || Lower.sgt(Upper))
     return APInt::getSignedMaxValue(getBitWidth());
   return getUpper() - 1;
 }
 
 APInt ConstantRange::getSignedMin() const {
-  if (!isWrappedSet()) {
-    if (getLower().sle(getUpper() - 1))
-      return getLower();
+  if (isFullSet() || (Lower.sgt(Upper) && !getUpper().isMinSignedValue()))
     return APInt::getSignedMinValue(getBitWidth());
-  }
-  if ((getUpper() - 1).slt(getLower())) {
-    if (!getUpper().isMinSignedValue())
-      return APInt::getSignedMinValue(getBitWidth());
-  }
   return getLower();
 }
 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D33815.101145.patch
Type: text/x-patch
Size: 1052 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20170602/4475f2bc/attachment.bin>