diff --git a/BaseTools/Conf/tools_def.template b/BaseTools/Conf/tools_def.template
index 994cae2588..13cf0f91b6 100755
--- a/BaseTools/Conf/tools_def.template
+++ b/BaseTools/Conf/tools_def.template
@@ -2130,7 +2130,7 @@ DEFINE CLANGDWARF_ARM_DLINK_FLAGS   = DEF(CLANGDWARF_ARM_TARGET) DEF(GCC_ARM_DLI
   DEBUG_CLANGDWARF_ARM_DLINK_FLAGS  = DEF(CLANGDWARF_ARM_DLINK_FLAGS) -flto -Wl,-O1 -fuse-ld=lld -L$(WORKSPACE)/BaseTools/Bin/GccLto -llto-arm -Wl,-plugin-opt=-pass-through=-llto-arm -Wl,--no-pie,--no-relax
   NOOPT_CLANGDWARF_ARM_CC_FLAGS     = DEF(CLANGDWARF_ARM_CC_FLAGS) $(PLATFORM_FLAGS) -O0
   NOOPT_CLANGDWARF_ARM_DLINK_FLAGS  = DEF(CLANGDWARF_ARM_DLINK_FLAGS) -fuse-ld=lld -Wl,--no-pie,--no-relax
-RELEASE_CLANGDWARF_ARM_CC_FLAGS     = DEF(CLANGDWARF_ARM_CC_FLAGS) $(PLATFORM_FLAGS) -flto -O3
+RELEASE_CLANGDWARF_ARM_CC_FLAGS     = DEF(CLANGDWARF_ARM_CC_FLAGS) $(PLATFORM_FLAGS) -flto -Oz
 RELEASE_CLANGDWARF_ARM_DLINK_FLAGS  = DEF(CLANGDWARF_ARM_DLINK_FLAGS) -flto -Wl,-O3 -fuse-ld=lld -L$(WORKSPACE)/BaseTools/Bin/GccLto -llto-arm -Wl,-plugin-opt=-pass-through=-llto-arm -Wl,--no-pie,--no-relax
 
 ##################
@@ -2176,7 +2176,7 @@ DEFINE CLANGDWARF_AARCH64_DLINK_FLAGS  = DEF(CLANGDWARF_AARCH64_TARGET) DEF(GCC_
   DEBUG_CLANGDWARF_AARCH64_DLINK_FLAGS = DEF(CLANGDWARF_AARCH64_DLINK_FLAGS) -flto -Wl,-O1 -fuse-ld=lld -L$(WORKSPACE)/BaseTools/Bin/GccLto -llto-aarch64 -Wl,-plugin-opt=-pass-through=-llto-aarch64 -Wl,--no-pie,--no-relax
   NOOPT_CLANGDWARF_AARCH64_CC_FLAGS    = DEF(CLANGDWARF_AARCH64_CC_FLAGS) $(PLATFORM_FLAGS) -O0
   NOOPT_CLANGDWARF_AARCH64_DLINK_FLAGS = DEF(CLANGDWARF_AARCH64_DLINK_FLAGS) -fuse-ld=lld -Wl,--no-pie,--no-relax
-RELEASE_CLANGDWARF_AARCH64_CC_FLAGS    = DEF(CLANGDWARF_AARCH64_CC_FLAGS) $(PLATFORM_FLAGS) -flto -O3
+RELEASE_CLANGDWARF_AARCH64_CC_FLAGS    = DEF(CLANGDWARF_AARCH64_CC_FLAGS) $(PLATFORM_FLAGS) -flto -Oz
 RELEASE_CLANGDWARF_AARCH64_DLINK_FLAGS = DEF(CLANGDWARF_AARCH64_DLINK_FLAGS) -flto -Wl,-O3 -fuse-ld=lld -L$(WORKSPACE)/BaseTools/Bin/GccLto -llto-aarch64 -Wl,-plugin-opt=-pass-through=-llto-aarch64 -Wl,--no-pie,--no-relax
 
 ##################
@@ -2228,7 +2228,7 @@ DEFINE CLANGDWARF_RISCV64_DLINK_FLAGS       = DEF(CLANGDWARF_RISCV64_TARGET) DEF
   DEBUG_CLANGDWARF_RISCV64_DLINK_FLAGS = DEF(CLANGDWARF_RISCV64_DLINK_FLAGS) -flto -Wl,-O1 -fuse-ld=lld -Wl,--no-pie,--no-relax
   NOOPT_CLANGDWARF_RISCV64_CC_FLAGS    = DEF(CLANGDWARF_RISCV64_CC_FLAGS) $(PLATFORM_FLAGS) -O0
   NOOPT_CLANGDWARF_RISCV64_DLINK_FLAGS = DEF(CLANGDWARF_RISCV64_DLINK_FLAGS) -fuse-ld=lld -Wl,--no-pie,--no-relax
-RELEASE_CLANGDWARF_RISCV64_CC_FLAGS    = DEF(CLANGDWARF_RISCV64_CC_FLAGS) $(PLATFORM_FLAGS) -flto -O3
+RELEASE_CLANGDWARF_RISCV64_CC_FLAGS    = DEF(CLANGDWARF_RISCV64_CC_FLAGS) $(PLATFORM_FLAGS) -flto -Oz
 RELEASE_CLANGDWARF_RISCV64_DLINK_FLAGS = DEF(CLANGDWARF_RISCV64_DLINK_FLAGS) -flto -Wl,-O3 -fuse-ld=lld -Wl,--no-pie,--no-relax
 
 #