[PR37339] Fix assertion in FunctionComparator::cmpInlineAsm

Fixes bug https://bugs.llvm.org/show_bug.cgi?id=37339.

InlineAsm is only uniqued if the FunctionTypes are exactly the
same, while cmpTypes() for example considers all pointer types
in the default address space to be the same. For this reason
the end of cmpInlineAsm() can be reached.

This patch replaces the unreachable assertion with a check that
the function types are not identical.

Differential Revision: https://reviews.llvm.org/D46495

Reviewers: jfb

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331990 91177308-0d34-0410-b5e6-96231b3b80d8

Author: whitequark

lib/Transforms/Utils/FunctionComparator.cpp

@@ -710,7 +710,7 @@ int FunctionComparator::cmpInlineAsm(const InlineAsm *L,
     return Res;
   if (int Res = cmpNumbers(L->getDialect(), R->getDialect()))
     return Res;
-  llvm_unreachable("InlineAsm blocks were not uniqued.");
+  assert(L->getFunctionType() != R->getFunctionType());
   return 0;
 }
 

test/Transforms/MergeFunc/inline-asm.ll

@@ -0,0 +1,53 @@
+; RUN: opt -mergefunc -S < %s | FileCheck %s
+
+; CHECK-LABEL: @int_ptr_arg_different
+; CHECK-NEXT: call void asm
+
+; CHECK-LABEL: @int_ptr_arg_same
+; CHECK-NEXT: %2 = bitcast i32* %0 to float*
+; CHECK-NEXT: tail call void @float_ptr_arg_same(float* %2)
+
+; CHECK-LABEL: @int_ptr_null
+; CHECK-NEXT: tail call void @float_ptr_null()
+
+; Used to satisfy minimum size limit
+declare void @stuff()
+
+; Can be merged
+define void @float_ptr_null() {
+  call void asm "nop", "r"(float* null)
+  call void @stuff()
+  ret void
+}
+
+define void @int_ptr_null() {
+  call void asm "nop", "r"(i32* null)
+  call void @stuff()
+  ret void
+}
+
+; Can be merged (uses same argument differing by pointer type)
+define void @float_ptr_arg_same(float*) {
+  call void asm "nop", "r"(float* %0)
+  call void @stuff()
+  ret void
+}
+
+define void @int_ptr_arg_same(i32*) {
+  call void asm "nop", "r"(i32* %0)
+  call void @stuff()
+  ret void
+}
+
+; Can not be merged (uses different arguments)
+define void @float_ptr_arg_different(float*, float*) {
+  call void asm "nop", "r"(float* %0)
+  call void @stuff()
+  ret void
+}
+
+define void @int_ptr_arg_different(i32*, i32*) {
+  call void asm "nop", "r"(i32* %1)
+  call void @stuff()
+  ret void
+}