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[Bug target/36424] New: avr-gcc use don't saved registers in ISR with -O3 ('-frename-registers' ) optimization
- From: "aesok at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 2 Jun 2008 17:56:00 -0000
- Subject: [Bug target/36424] New: avr-gcc use don't saved registers in ISR with -O3 ('-frename-registers' ) optimization
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
Testcase:
#include <avr/io.h>
#include <avr/interrupt.h>
volatile unsigned char UART_RxChar;
volatile unsigned char UART_ReceivedChar;
SIGNAL(SIG_USART_RECV)
{
/* Indicate that the UART has received a character */
UART_ReceivedChar = 1;
/* Store received character */
UART_RxChar = UDR;
}
Request: use -frename-registers optimization, enabled on -O3.
Result code:
.global __vector_13
.type __vector_13, @function
__vector_13:
.LFB2:
.LM1:
push __zero_reg__
push r0
in r0,__SREG__
push r0
clr __zero_reg__
push r24
/* prologue: Signal */
/* frame size = 0 */
.LM2:
ldi r26,lo8(1)
sts UART_ReceivedChar,r26
.LM3:
lds r24,198
sts UART_RxChar,r24
/* epilogue start */
.LM4:
pop r24
pop r0
out __SREG__,r0
pop r0
pop __zero_reg__
reti
R26 register used in ISR but don't saved/restored.
To fix bug, need define HARD_REGNO_RENAME_OK macro in config/avr.h
Anatoly.
--
Summary: avr-gcc use don't saved registers in ISR with -O3 ('-
frename-registers' ) optimization
Product: gcc
Version: 4.4.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: aesok at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36424