Index: llvm/lib/IR/ConstantFold.cpp
===================================================================
--- llvm/lib/IR/ConstantFold.cpp
+++ llvm/lib/IR/ConstantFold.cpp
@@ -1751,9 +1751,15 @@
     case Instruction::FPToSI:
       break; // We can't evaluate floating point casts or truncations.
 
+    case Instruction::BitCast:
+      // If this is a global value cast, check to see if the RHS is also a
+      // GlobalValue.
+      if (const GlobalValue *GV = dyn_cast<GlobalValue>(CE1Op0))
+        if (const GlobalValue *GV2 = dyn_cast<GlobalValue>(V2))
+          return areGlobalsPotentiallyEqual(GV, GV2);
+      LLVM_FALLTHROUGH;
     case Instruction::UIToFP:
     case Instruction::SIToFP:
-    case Instruction::BitCast:
     case Instruction::ZExt:
     case Instruction::SExt:
       // We can't evaluate floating point casts or truncations.
Index: llvm/test/Transforms/InstCombine/icmp-bitcast-func.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/InstCombine/icmp-bitcast-func.ll
@@ -0,0 +1,20 @@
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+declare i32 @f32(i32**, i32**)
+
+declare i32 @f64(i64**, i64**)
+
+define i1 @icmp_func() {
+; CHECK-LABEL: @icmp_func(
+; CHECK: ret i1 false
+  %cmp = icmp eq i32 (i8*, i8*)* bitcast (i32 (i32**, i32**)* @f32 to i32 (i8*, i8*)*), bitcast (i32 (i64**, i64**)* @f64 to i32 (i8*, i8*)*)
+  ret i1 %cmp
+}
+
+define i1 @icmp_fptr(i32 (i8*, i8*)*) {
+; CHECK-LABEL: @icmp_fptr(
+; CHECK: %cmp = icmp ne i32 (i8*, i8*)* %0, bitcast (i32 (i32**, i32**)* @f32 to i32 (i8*, i8*)*)
+; CHECK: ret i1 %cmp
+  %cmp = icmp ne i32 (i8*, i8*)* bitcast (i32 (i32**, i32**)* @f32 to i32 (i8*, i8*)*), %0
+  ret i1 %cmp
+}
Index: llvm/test/Transforms/InstCombine/pr32686.ll
===================================================================
--- llvm/test/Transforms/InstCombine/pr32686.ll
+++ llvm/test/Transforms/InstCombine/pr32686.ll
@@ -1,8 +1,9 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt -S -instcombine %s | FileCheck %s
 
-@a = external global i8
+@a = common global i8 0, align 1
 @b = external global i32
+@a2 = external global i8
 
 define void @tinkywinky() {
 ; CHECK-LABEL: @tinkywinky(
@@ -21,3 +22,18 @@
   store i32 %or, i32* @b, align 4
   ret void
 }
+
+define void @tinkywinky2() {
+; CHECK-LABEL: @tinkywinky2(
+; CHECK-NEXT:    store i32 3, i32* @b, align 4
+; CHECK-NEXT:    ret void
+;
+  %patatino = load i8, i8* @a2
+  %tobool = icmp ne i8 %patatino, 0
+  %lnot = xor i1 %tobool, true
+  %lnot.ext = zext i1 %lnot to i32
+  %or = or i32 xor (i32 zext (i1 icmp ne (i32* bitcast (i8* @a2 to i32*), i32* @b) to i32), i32 2), %lnot.ext
+  store i32 %or, i32* @b, align 4
+  ret void
+}
+
Index: llvm/test/Transforms/SCCP/ip-ranges-select.ll
===================================================================
--- llvm/test/Transforms/SCCP/ip-ranges-select.ll
+++ llvm/test/Transforms/SCCP/ip-ranges-select.ll
@@ -107,7 +107,8 @@
   ret i1 %res
 }
 
-@GV = external global i32
+@GV = common global i32 0, align 4
+@GV2 = external global i32
 
 define i32 @f3_constantexpr_cond(i32 %x, i32 %y) {
 ; CHECK-LABEL: define i32 @f3_constantexpr_cond(i32 %x, i32 %y)
@@ -118,6 +119,15 @@
   ret i32 %sel.1
 }
 
+define i32 @f3_constantexpr_cond2(i32 %x, i32 %y) {
+; CHECK-LABEL: define i32 @f3_constantexpr_cond2(i32 %x, i32 %y)
+; CHECK-NEXT:   %sel.1 = select i1 false, i32 %x, i32 %y
+; CHECK-NEXT:   ret i32 %sel.1
+;
+  %sel.1 = select i1 icmp eq (i32* bitcast (i32 (i32, i32)* @f3_constantexpr_cond to i32*), i32* @GV2), i32 %x, i32 %y
+  ret i32 %sel.1
+}
+
 define i32 @caller3(i32 %y) {
 ; CHECK-LABEL:  define i32 @caller3(i32 %y) {
 ; CHECK-NEXT:    %call.1 = tail call i32 @f3_constantexpr_cond(i32 10, i32 %y)
Index: llvm/test/Transforms/SCCP/undef-resolve.ll
===================================================================
--- llvm/test/Transforms/SCCP/undef-resolve.ll
+++ llvm/test/Transforms/SCCP/undef-resolve.ll
@@ -254,7 +254,8 @@
   ret i64 %e
 }
 
-@GV = external global i32
+@GV = common global i32 0, align 4
+@GV2 = external global i32
 
 define i32 @test11(i1 %tobool) {
 ; CHECK-LABEL: @test11(
@@ -276,3 +277,15 @@
   %t = fneg double undef
   ret double %t
 }
+
+
+define i32 @test13(i1 %tobool) {
+; CHECK-LABEL: @test13(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[SHR4:%.*]] = ashr i32 undef, 0
+; CHECK-NEXT:    ret i32 [[SHR4]]
+;
+entry:
+  %shr4 = ashr i32 undef, zext (i1 icmp eq (i32* bitcast (i32 (i1)* @test11 to i32*), i32* @GV2) to i32)
+  ret i32 %shr4
+}