| Message ID | 20200721164527.lytu6e5ypi6lz6e7@jozef-acer-manjaro |
|---|---|
| State | New |
| Headers | show |
| Series | [committed] MSP430: Define NO_FUNCTION_CSE | expand |
diff --git a/gcc/config/msp430/msp430.h b/gcc/config/msp430/msp430.h index f198981ad9e..e97e833a10c 100644 --- a/gcc/config/msp430/msp430.h +++ b/gcc/config/msp430/msp430.h @@ -257,6 +257,11 @@ extern const char *msp430_get_linker_devices_include_path (int, const char **); msp430_return_addr_rtx (COUNT) #define SLOW_BYTE_ACCESS 0 + +/* Calling a constant function address costs the same number of clock + cycles as calling an address stored in a register. However, in terms of + instruction length, calling a constant address is more expensive. */ +#define NO_FUNCTION_CSE (optimize >= 2 && !optimize_size) /* Register Usage */
Calling a constant function address costs the same number of clock cycles as calling an address stored in a register. However, in terms of instruction length, calling a constant address is more expensive. Set NO_FUNCTION_CSE to true, only when optimizing for speed. Committed the attached patch as obvious. Successfully regtested on trunk for msp430-elf. From 111afded7fdf46ce14972aa8a72c26c9a180ab70 Mon Sep 17 00:00:00 2001 From: Jozef Lawrynowicz <jozef.l@mittosystems.com> Date: Tue, 21 Jul 2020 17:24:03 +0100 Subject: [PATCH] MSP430: Define NO_FUNCTION_CSE Calling a constant function address costs the same number of clock cycles as calling an address stored in a register. However, in terms of instruction length, calling a constant address is more expensive. Set NO_FUNCTION_CSE to true, only when optimizing for speed. gcc/ChangeLog: * config/msp430/msp430.h (NO_FUNCTION_CSE): Set to true at -O2 and above. --- gcc/config/msp430/msp430.h | 5 +++++ 1 file changed, 5 insertions(+)