Index: lib/asan/asan_asm_instrumentation.S
===================================================================
--- lib/asan/asan_asm_instrumentation.S
+++ lib/asan/asan_asm_instrumentation.S
@@ -324,7 +324,7 @@
 .globl __sanitizer_sanitize_store1
 .type __sanitizer_sanitize_store1, @function
 __sanitizer_sanitize_store1:
-  subq $128, %rsp
+  leaq -128(%rsp), %rsp
   pushq %rax
   pushq %rcx
   pushfq
@@ -347,14 +347,14 @@
   popfq
   popq %rcx
   popq %rax
-  addq $128, %rsp
+  leaq 128(%rsp), %rsp
   ret
 // Sanitize 1-byte load. Takes one 8-byte address as an argument in %rdi,
 // nothing is returned.
 .globl __sanitizer_sanitize_load1
 .type __sanitizer_sanitize_load1, @function
 __sanitizer_sanitize_load1:
-  subq $128, %rsp
+  leaq -128(%rsp), %rsp
   pushq %rax
   pushq %rcx
   pushfq
@@ -377,14 +377,14 @@
   popfq
   popq %rcx
   popq %rax
-  addq $128, %rsp
+  leaq 128(%rsp), %rsp
   ret
 // Sanitize 2-byte store. Takes one 8-byte address as an argument in %rdi,
 // nothing is returned.
 .globl __sanitizer_sanitize_store2
 .type __sanitizer_sanitize_store2, @function
 __sanitizer_sanitize_store2:
-  subq $128, %rsp
+  leaq -128(%rsp), %rsp
   pushq %rax
   pushq %rcx
   pushfq
@@ -408,14 +408,14 @@
   popfq
   popq %rcx
   popq %rax
-  addq $128, %rsp
+  leaq 128(%rsp), %rsp
   ret
 // Sanitize 2-byte load. Takes one 8-byte address as an argument in %rdi,
 // nothing is returned.
 .globl __sanitizer_sanitize_load2
 .type __sanitizer_sanitize_load2, @function
 __sanitizer_sanitize_load2:
-  subq $128, %rsp
+  leaq -128(%rsp), %rsp
   pushq %rax
   pushq %rcx
   pushfq
@@ -439,14 +439,14 @@
   popfq
   popq %rcx
   popq %rax
-  addq $128, %rsp
+  leaq 128(%rsp), %rsp
   ret
 // Sanitize 4-byte store. Takes one 8-byte address as an argument in %rdi,
 // nothing is returned.
 .globl __sanitizer_sanitize_store4
 .type __sanitizer_sanitize_store4, @function
 __sanitizer_sanitize_store4:
-  subq $128, %rsp
+  leaq -128(%rsp), %rsp
   pushq %rax
   pushq %rcx
   pushfq
@@ -470,14 +470,14 @@
   popfq
   popq %rcx
   popq %rax
-  addq $128, %rsp
+  leaq 128(%rsp), %rsp
   ret
 // Sanitize 4-byte load. Takes one 8-byte address as an argument in %rdi,
 // nothing is returned.
 .globl __sanitizer_sanitize_load4
 .type __sanitizer_sanitize_load4, @function
 __sanitizer_sanitize_load4:
-  subq $128, %rsp
+  leaq -128(%rsp), %rsp
   pushq %rax
   pushq %rcx
   pushfq
@@ -501,14 +501,14 @@
   popfq
   popq %rcx
   popq %rax
-  addq $128, %rsp
+  leaq 128(%rsp), %rsp
   ret
 // Sanitize 8-byte store. Takes one 8-byte address as an argument in %rdi,
 // nothing is returned.
 .globl __sanitizer_sanitize_store8
 .type __sanitizer_sanitize_store8, @function
 __sanitizer_sanitize_store8:
-  subq $128, %rsp
+  leaq -128(%rsp), %rsp
   pushq %rax
   pushfq
   movq %rdi, %rax
@@ -523,14 +523,14 @@
 .sanitize_store8_done:
   popfq
   popq %rax
-  addq $128, %rsp
+  leaq 128(%rsp), %rsp
   ret
 // Sanitize 8-byte load. Takes one 8-byte address as an argument in %rdi,
 // nothing is returned.
 .globl __sanitizer_sanitize_load8
 .type __sanitizer_sanitize_load8, @function
 __sanitizer_sanitize_load8:
-  subq $128, %rsp
+  leaq -128(%rsp), %rsp
   pushq %rax
   pushfq
   movq %rdi, %rax
@@ -545,14 +545,14 @@
 .sanitize_load8_done:
   popfq
   popq %rax
-  addq $128, %rsp
+  leaq 128(%rsp), %rsp
   ret
 // Sanitize 16-byte store. Takes one 8-byte address as an argument in %rdi,
 // nothing is returned.
 .globl __sanitizer_sanitize_store16
 .type __sanitizer_sanitize_store16, @function
 __sanitizer_sanitize_store16:
-  subq $128, %rsp
+  leaq -128(%rsp), %rsp
   pushq %rax
   pushfq
   movq %rdi, %rax
@@ -567,14 +567,14 @@
 .sanitize_store16_done:
   popfq
   popq %rax
-  addq $128, %rsp
+  leaq 128(%rsp), %rsp
   ret
 // Sanitize 16-byte load. Takes one 8-byte address as an argument in %rdi,
 // nothing is returned.
 .globl __sanitizer_sanitize_load16
 .type __sanitizer_sanitize_load16, @function
 __sanitizer_sanitize_load16:
-  subq $128, %rsp
+  leaq -128(%rsp), %rsp
   pushq %rax
   pushfq
   movq %rdi, %rax
@@ -589,7 +589,7 @@
 .sanitize_load16_done:
   popfq
   popq %rax
-  addq $128, %rsp
+  leaq 128(%rsp), %rsp
   ret
 #endif // defined(__x86_64__)
 /* We do not need executable stack. */
Index: lib/asan/scripts/gen_asm_instrumentation.sh
===================================================================
--- lib/asan/scripts/gen_asm_instrumentation.sh
+++ lib/asan/scripts/gen_asm_instrumentation.sh
@@ -181,7 +181,7 @@
 .globl $(func_name $at $as)
 .type $(func_name $at $as), @function
 $(func_name $at $as):
-  subq \$128, %rsp
+  leaq -128(%rsp), %rsp
   pushq %rax
   pushq %rcx
   pushfq
@@ -211,7 +211,7 @@
   popfq
   popq %rcx
   popq %rax
-  addq \$128, %rsp
+  leaq 128(%rsp), %rsp
   ret
 EOF
   done
@@ -228,7 +228,7 @@
 .globl $(func_name $at $as)
 .type $(func_name $at $as), @function
 $(func_name $at $as):
-  subq \$128, %rsp
+  leaq -128(%rsp), %rsp
   pushq %rax
   pushfq
   movq %rdi, %rax
@@ -248,7 +248,7 @@
 $(func_label $at $as):
   popfq
   popq %rax
-  addq \$128, %rsp
+  leaq 128(%rsp), %rsp
   ret
 EOF
   done
Index: lib/asan/tests/CMakeLists.txt
===================================================================
--- lib/asan/tests/CMakeLists.txt
+++ lib/asan/tests/CMakeLists.txt
@@ -60,6 +60,7 @@
   ${ASAN_UNITTEST_COMMON_CFLAGS}
   -fsanitize=address
   "-fsanitize-blacklist=${ASAN_BLACKLIST_FILE}"
+  -mllvm -asan-instrument-assembly
 )
 
 if(NOT MSVC)
Index: lib/asan/tests/asan_asm_test.cc
===================================================================
--- lib/asan/tests/asan_asm_test.cc
+++ lib/asan/tests/asan_asm_test.cc
@@ -197,6 +197,40 @@
   delete [] buf;
 }
 
+#if defined(__x86_64__)
+
+void TestFlags() {
+  long magic = 0x1234;
+  long r = 0x0;
+  __asm__("xorq %%rax, %%rax  \n\t"
+          "movq (%[p]), %%rax \n\t"
+          "sete %%al          \n\t"
+          "movzbq %%al, %[r]  \n\t"
+          : [r] "=r"(r)
+          : [p] "r"(&magic)
+          : "rax", "memory");
+  ASSERT_EQ(0x1, r);
+}
+
+#endif // defined(__x86_64__)
+
+#if defined(__i386__)
+
+void TestFlags() {
+  long magic = 0x1234;
+  long r = 0x0;
+  __asm__("xorl %%eax, %%eax  \n\t"
+          "movl (%[p]), %%eax \n\t"
+          "sete %%al          \n\t"
+          "movzbl %%al, %[r]  \n\t"
+          : [r] "=r"(r)
+          : [p] "r"(&magic)
+          : "eax", "memory");
+  ASSERT_EQ(0x1, r);
+}
+
+#endif // defined(__i386__)
+
 } // End of anonymous namespace
 
 TEST(AddressSanitizer, asm_rw) {
@@ -211,6 +245,8 @@
   TestAsmRead<U4>("READ of size 4");
   TestAsmRead<U8>("READ of size 8");
   TestAsmRead<__m128i>("READ of size 16");
+
+  TestFlags();
 }
 
 #endif // defined(__x86_64__) || (defined(__i386__) && defined(__SSE2__))