enhance vmcore to know that udiv's can be exact, and add a trivial

instcombine xform to exercise this.

Nothing forms exact udivs yet though.  This is progress on PR8862



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124992 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 10 insertions, 7 deletions

diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index adcad74989..a744d83302 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -1090,8 +1090,9 @@ bool BitcodeReader::ParseConstants() {
               Flags |= OverflowingBinaryOperator::NoSignedWrap;
             if (Record[3] & (1 << bitc::OBO_NO_UNSIGNED_WRAP))
               Flags |= OverflowingBinaryOperator::NoUnsignedWrap;
-          } else if (Opc == Instruction::SDiv) {
-            if (Record[3] & (1 << bitc::SDIV_EXACT))
+          } else if (Opc == Instruction::SDiv ||
+                     Opc == Instruction::UDiv) {
+            if (Record[3] & (1 << bitc::PEO_EXACT))
               Flags |= SDivOperator::IsExact;
           }
         }
@@ -1905,8 +1906,9 @@ bool BitcodeReader::ParseFunctionBody(Function *F) {
             cast<BinaryOperator>(I)->setHasNoSignedWrap(true);
           if (Record[OpNum] & (1 << bitc::OBO_NO_UNSIGNED_WRAP))
             cast<BinaryOperator>(I)->setHasNoUnsignedWrap(true);
-        } else if (Opc == Instruction::SDiv) {
-          if (Record[OpNum] & (1 << bitc::SDIV_EXACT))
+        } else if (Opc == Instruction::SDiv ||
+                   Opc == Instruction::UDiv) {
+          if (Record[OpNum] & (1 << bitc::PEO_EXACT))
             cast<BinaryOperator>(I)->setIsExact(true);
         }
       }
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index 702a611cbe..f8ef8c668c 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -470,9 +470,10 @@ static uint64_t GetOptimizationFlags(const Value *V) {
       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
     if (OBO->hasNoUnsignedWrap())
       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
-  } else if (const SDivOperator *Div = dyn_cast<SDivOperator>(V)) {
-    if (Div->isExact())
-      Flags |= 1 << bitc::SDIV_EXACT;
+  } else if (const PossiblyExactOperator *PEO =
+               dyn_cast<PossiblyExactOperator>(V)) {
+    if (PEO->isExact())
+      Flags |= 1 << bitc::PEO_EXACT;
   }
 
   return Flags;