diff --git a/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/Inputs/amdgpu_no_merge_comments.ll b/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/Inputs/amdgpu_no_merge_comments.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/Inputs/amdgpu_no_merge_comments.ll
@@ -0,0 +1,9 @@
+; RUN: llc -O0 -mtriple=amdgcn- -mcpu=gfx900 < %s | FileCheck -check-prefixes=GCN,GFX9-O0 %s
+; RUN: llc -mtriple=amdgcn- -mcpu=gfx900 < %s | FileCheck -check-prefixes=GCN,GFX9-O3 %s
+
+define hidden i32 @main(i32 %a) {
+  %add = add i32 %a, %a
+  %mul = mul i32 %add, %a
+  %sub = sub i32 %mul, %add
+  ret i32 %sub
+}
diff --git a/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/Inputs/amdgpu_no_merge_comments.ll.expected b/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/Inputs/amdgpu_no_merge_comments.ll.expected
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/Inputs/amdgpu_no_merge_comments.ll.expected
@@ -0,0 +1,27 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -O0 -mtriple=amdgcn- -mcpu=gfx900 < %s | FileCheck -check-prefixes=GCN,GFX9-O0 %s
+; RUN: llc -mtriple=amdgcn- -mcpu=gfx900 < %s | FileCheck -check-prefixes=GCN,GFX9-O3 %s
+
+define hidden i32 @main(i32 %a) {
+; GFX9-O0-LABEL: main:
+; GFX9-O0:       ; %bb.0:
+; GFX9-O0-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX9-O0-NEXT:    v_add_u32_e64 v1, v0, v0
+; GFX9-O0-NEXT:    ; implicit-def: $sgpr4
+; GFX9-O0-NEXT:    ; implicit-def: $sgpr4
+; GFX9-O0-NEXT:    v_mul_lo_u32 v0, v1, v0
+; GFX9-O0-NEXT:    v_sub_u32_e64 v0, v0, v1
+; GFX9-O0-NEXT:    s_setpc_b64 s[30:31]
+;
+; GFX9-O3-LABEL: main:
+; GFX9-O3:       ; %bb.0:
+; GFX9-O3-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX9-O3-NEXT:    v_add_u32_e32 v1, v0, v0
+; GFX9-O3-NEXT:    v_mul_lo_u32 v0, v1, v0
+; GFX9-O3-NEXT:    v_sub_u32_e32 v0, v0, v1
+; GFX9-O3-NEXT:    s_setpc_b64 s[30:31]
+  %add = add i32 %a, %a
+  %mul = mul i32 %add, %a
+  %sub = sub i32 %mul, %add
+  ret i32 %sub
+}
diff --git a/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/amdgpu-no-merge-comments.test b/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/amdgpu-no-merge-comments.test
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/amdgpu-no-merge-comments.test
@@ -0,0 +1,5 @@
+# REQUIRES: amdgpu-registered-target
+## Check that functions with different IR comments in the output are not merged
+
+# RUN: cp -f %S/Inputs/amdgpu_no_merge_comments.ll %t.ll && %update_llc_test_checks %t.ll
+# RUN: diff -u %S/Inputs/amdgpu_no_merge_comments.ll.expected %t.ll
diff --git a/llvm/utils/UpdateTestChecks/common.py b/llvm/utils/UpdateTestChecks/common.py
--- a/llvm/utils/UpdateTestChecks/common.py
+++ b/llvm/utils/UpdateTestChecks/common.py
@@ -268,7 +268,7 @@
     self.extrascrub = extra
     self.args_and_sig = args_and_sig
     self.attrs = attrs
-  def is_same_except_arg_names(self, extrascrub, args_and_sig, attrs):
+  def is_same_except_arg_names(self, extrascrub, args_and_sig, attrs, is_asm):
     arg_names = set()
     def drop_arg_names(match):
         arg_names.add(match.group(variable_group_in_ir_value_match))
@@ -287,6 +287,11 @@
     ans1 = IR_VALUE_RE.sub(drop_arg_names, args_and_sig)
     if ans0 != ans1:
         return False
+    if is_asm:
+        # Check without replacements, the replacements are not applied to the
+        # body for asm checks.
+        return self.extrascrub == extrascrub
+
     es0 = IR_VALUE_RE.sub(repl_arg_names, self.extrascrub)
     es1 = IR_VALUE_RE.sub(repl_arg_names, extrascrub)
     es0 = SCRUB_IR_COMMENT_RE.sub(r'', es0)
@@ -325,7 +330,7 @@
   def global_var_dict(self):
     return self._global_var_dict
 
-  def process_run_line(self, function_re, scrubber, raw_tool_output, prefixes):
+  def process_run_line(self, function_re, scrubber, raw_tool_output, prefixes, is_asm):
     build_global_values_dictionary(self._global_var_dict, raw_tool_output, prefixes)
     for m in function_re.finditer(raw_tool_output):
       if not m:
@@ -391,7 +396,8 @@
                 self._func_dict[prefix][func].is_same_except_arg_names(
                 scrubbed_extra,
                 args_and_sig,
-                attrs)):
+                attrs,
+                is_asm)):
               self._func_dict[prefix][func].scrub = scrubbed_extra
               self._func_dict[prefix][func].args_and_sig = args_and_sig
               continue
diff --git a/llvm/utils/update_analyze_test_checks.py b/llvm/utils/update_analyze_test_checks.py
--- a/llvm/utils/update_analyze_test_checks.py
+++ b/llvm/utils/update_analyze_test_checks.py
@@ -127,7 +127,7 @@
       # Split analysis outputs by "Printing analysis " declarations.
       for raw_tool_output in re.split(r'Printing analysis ', raw_tool_outputs):
         builder.process_run_line(common.ANALYZE_FUNCTION_RE, common.scrub_body,
-                                 raw_tool_output, prefixes)
+                                 raw_tool_output, prefixes, False)
 
     func_dict = builder.finish_and_get_func_dict()
     is_in_function = False
diff --git a/llvm/utils/update_cc_test_checks.py b/llvm/utils/update_cc_test_checks.py
--- a/llvm/utils/update_cc_test_checks.py
+++ b/llvm/utils/update_cc_test_checks.py
@@ -213,7 +213,7 @@
   if '-emit-llvm' in clang_args:
     builder.process_run_line(
             common.OPT_FUNCTION_RE, common.scrub_body, raw_tool_output,
-            prefixes)
+            prefixes, False)
   else:
     print('The clang command line should include -emit-llvm as asm tests '
           'are discouraged in Clang testsuite.', file=sys.stderr)
diff --git a/llvm/utils/update_llc_test_checks.py b/llvm/utils/update_llc_test_checks.py
--- a/llvm/utils/update_llc_test_checks.py
+++ b/llvm/utils/update_llc_test_checks.py
@@ -129,7 +129,7 @@
         triple = asm.get_triple_from_march(march_in_cmd)
 
       scrubber, function_re = asm.get_run_handler(triple)
-      builder.process_run_line(function_re, scrubber, raw_tool_output, prefixes)
+      builder.process_run_line(function_re, scrubber, raw_tool_output, prefixes, True)
 
     func_dict = builder.finish_and_get_func_dict()
 
diff --git a/llvm/utils/update_test_checks.py b/llvm/utils/update_test_checks.py
--- a/llvm/utils/update_test_checks.py
+++ b/llvm/utils/update_test_checks.py
@@ -124,7 +124,7 @@
                                            ti.path, preprocess_cmd=preprocess_cmd,
                                            verbose=ti.args.verbose)
       builder.process_run_line(common.OPT_FUNCTION_RE, common.scrub_body,
-              raw_tool_output, prefixes)
+              raw_tool_output, prefixes, False)
 
     func_dict = builder.finish_and_get_func_dict()
     is_in_function = False