[llvm] r355818 - [MIPS GlobalISel] Silence uninitialized variable warning

[Benjamin Kramer via llvm-commits]

Author: d0k
Date: Mon Mar 11 03:39:15 2019
New Revision: 355818

URL: http://llvm.org/viewvc/llvm-project?rev=355818&view=rev
Log:
[MIPS GlobalISel] Silence uninitialized variable warning

The control flow here cannot ever use the uninitialized value, but it's
too hard for the compiler to figure that out. Clang warns:

llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:2600:28: error: variable 'CarrySum' is used uninitialized whenever 'for' loop exits because its condition is false [-Werror,-Wsometimes-uninitialized]
      for (unsigned i = 2; i < Factors.size(); ++i)
                           ^~~~~~~~~~~~~~~~~~
llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:2604:26: note: uninitialized use occurs here
    CarrySumPrevDstIdx = CarrySum;
                         ^~~~~~~~
llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:2600:28: note: remove the condition if it is always true
      for (unsigned i = 2; i < Factors.size(); ++i)
                           ^~~~~~~~~~~~~~~~~~
llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:2583:22: note: initialize the variable 'CarrySum' to silence this warning
    unsigned CarrySum;
                     ^
                      = 0

Modified:
    llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp

Modified: llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp?rev=355818&r1=355817&r2=355818&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp (original)
+++ llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp Mon Mar 11 03:39:15 2019
@@ -2581,7 +2581,7 @@ void LegalizerHelper::multiplyRegisters(
       Factors.push_back(CarrySumPrevDstIdx);
     }
 
-    unsigned CarrySum;
+    unsigned CarrySum = 0;
     // Add all factors and accumulate all carries into CarrySum.
     if (DstIdx != DstParts - 1) {
       MachineInstrBuilder Uaddo =