Index: llvm/trunk/lib/Transforms/IPO/MergeFunctions.cpp
===================================================================
--- llvm/trunk/lib/Transforms/IPO/MergeFunctions.cpp
+++ llvm/trunk/lib/Transforms/IPO/MergeFunctions.cpp
@@ -1082,11 +1082,8 @@
         Value *OpR = InstR->getOperand(i);
         if (int Res = cmpValues(OpL, OpR))
           return Res;
-        if (int Res = cmpNumbers(OpL->getValueID(), OpR->getValueID()))
-          return Res;
-        // TODO: Already checked in cmpOperation
-        if (int Res = cmpTypes(OpL->getType(), OpR->getType()))
-          return Res;
+        // cmpValues should ensure this is true.
+        assert(cmpTypes(OpL->getType(), OpR->getType()) == 0);
       }
     }
 
Index: llvm/trunk/test/Transforms/MergeFunc/merge-const-ptr-and-int.ll
===================================================================
--- llvm/trunk/test/Transforms/MergeFunc/merge-const-ptr-and-int.ll
+++ llvm/trunk/test/Transforms/MergeFunc/merge-const-ptr-and-int.ll
@@ -0,0 +1,20 @@
+; RUN: opt -mergefunc -S < %s | FileCheck %s
+; RUN: opt -mergefunc -S < %s | FileCheck -check-prefix=MERGE %s
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+
+; Afunc and Bfunc differ only in that one returns i64, the other a pointer.
+; These should be merged.
+define internal i64 @Afunc(i32* %P, i32* %Q) {
+; CHECK-LABEL: define internal i64 @Afunc
+  store i32 4, i32* %P
+  store i32 6, i32* %Q
+  ret i64 0
+}
+
+define internal i64* @Bfunc(i32* %P, i32* %Q) {
+; MERGE-NOT: @Bfunc
+  store i32 4, i32* %P
+  store i32 6, i32* %Q
+  ret i64* null
+}
+
Index: llvm/trunk/test/Transforms/MergeFunc/merge-different-vector-types.ll
===================================================================
--- llvm/trunk/test/Transforms/MergeFunc/merge-different-vector-types.ll
+++ llvm/trunk/test/Transforms/MergeFunc/merge-different-vector-types.ll
@@ -0,0 +1,18 @@
+; RUN: opt -mergefunc -S < %s | FileCheck %s
+; RUN: opt -mergefunc -S < %s | FileCheck -check-prefix=MERGE %s
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+
+; Merging should still work even if the values are wrapped in a vector.
+define internal <2 x i64> @Mfunc(i32* %P, i32* %Q) {
+; CHECK-LABEL: define internal <2 x i64> @Mfunc
+  store i32 1, i32* %P
+  store i32 1, i32* %Q
+  ret <2 x i64> <i64 0, i64 0>
+}
+
+define internal <2 x i64*> @Nfunc(i32* %P, i32* %Q) {
+; MERGE-NOT: @Nfunc
+  store i32 1, i32* %P
+  store i32 1, i32* %Q
+  ret <2 x i64*> <i64* null, i64* null>
+}
Index: llvm/trunk/test/Transforms/MergeFunc/no-merge-ptr-different-sizes.ll
===================================================================
--- llvm/trunk/test/Transforms/MergeFunc/no-merge-ptr-different-sizes.ll
+++ llvm/trunk/test/Transforms/MergeFunc/no-merge-ptr-different-sizes.ll
@@ -0,0 +1,24 @@
+; RUN: opt -mergefunc -S < %s | FileCheck %s
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+
+; These should not be merged, as the datalayout says a pointer is 64 bits. No
+; sext/zext is specified, so these functions could lower differently.
+define internal i32 @Ffunc(i32* %P, i32* %Q) {
+; CHECK-LABEL: define internal i32 @Ffunc
+; CHECK-NEXT: store
+; CHECK-NEXT: store
+; CHECK-NEXT: ret
+  store i32 1, i32* %P
+  store i32 3, i32* %Q
+  ret i32 0
+}
+
+define internal i64* @Gfunc(i32* %P, i32* %Q) {
+; CHECK-LABEL: define internal i64* @Gfunc
+; CHECK-NEXT: store
+; CHECK-NEXT: store
+; CHECK-NEXT: ret
+  store i32 1, i32* %P
+  store i32 3, i32* %Q
+  ret i64* null
+}
Index: llvm/trunk/test/Transforms/MergeFunc/no-merge-ptr-int-different-values.ll
===================================================================
--- llvm/trunk/test/Transforms/MergeFunc/no-merge-ptr-int-different-values.ll
+++ llvm/trunk/test/Transforms/MergeFunc/no-merge-ptr-int-different-values.ll
@@ -0,0 +1,23 @@
+; RUN: opt -mergefunc -S < %s | FileCheck %s
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+
+; These should not be merged, as 1 != 0.
+define internal i64 @Ifunc(i32* %P, i32* %Q) {
+; CHECK-LABEL: define internal i64 @Ifunc
+; CHECK-NEXT: store
+; CHECK-NEXT: store
+; CHECK-NEXT: ret
+  store i32 10, i32* %P
+  store i32 10, i32* %Q
+  ret i64 1
+}
+
+define internal i64* @Jfunc(i32* %P, i32* %Q) {
+; CHECK-LABEL: define internal i64* @Jfunc
+; CHECK-NEXT: store
+; CHECK-NEXT: store
+; CHECK-NEXT: ret
+  store i32 10, i32* %P
+  store i32 10, i32* %Q
+  ret i64* null
+}
Index: llvm/trunk/test/Transforms/MergeFunc/undef-different-types.ll
===================================================================
--- llvm/trunk/test/Transforms/MergeFunc/undef-different-types.ll
+++ llvm/trunk/test/Transforms/MergeFunc/undef-different-types.ll
@@ -0,0 +1,21 @@
+; RUN: opt -mergefunc -S < %s | FileCheck %s
+; RUN: opt -mergefunc -S < %s | FileCheck -check-prefix=MERGE %s
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+
+; Cfunc and Dfunc differ only in that one returns i64, the other a pointer, and
+; both return undef. They should be merged. Note undef cannot be merged with
+; anything else, because this implies the ordering will be inconsistent (i.e.
+; -1 == undef and undef == 1, but -1 < 1, so we must have undef != <any int>).
+define internal i64 @Cfunc(i32* %P, i32* %Q) {
+; CHECK-LABEL: define internal i64 @Cfunc
+  store i32 4, i32* %P
+  store i32 6, i32* %Q
+  ret i64 undef
+}
+
+define internal i64* @Dfunc(i32* %P, i32* %Q) {
+; MERGE-NOT: @Dfunc
+  store i32 4, i32* %P
+  store i32 6, i32* %Q
+  ret i64* undef
+}