optimization/10157: internal compiler error: in extract_insn, at recog.c:2188

[Peter van Hoof]

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10157

This somewhat shorter version triggers the bug with -O2 instead of -O3:

void g() {
	while( 1 ) {
		int i,n;
		double p,r;
		for( i=0; i < n; i++ )
			if( p > 1. )
				for( i=0; i < n; i++ )
					r += 2.;
	}
}

scooby>	gcc -c -O2 -ffast-math h3.c
h3.c: In function `g':
h3.c:10: error: unrecognizable insn:
(insn:HI 130 129 8 0 0 (set (reg:CCFPE 127)
         (compare:CCFPE (reg/v:DF 109 [ p ])
             (reg:DF 111))) -1 (insn_list 129 (nil))
     (expr_list:REG_DEAD (reg/v:DF 109 [ p ])
         (expr_list:REG_DEAD (reg:DF 111)
             (expr_list:REG_EQUAL (compare:CCFPE (reg/v:DF 109 [ p ])
                     (const_double:DF 1.0e+0 [0x0.8p+1]))
                 (nil)))))
h3.c:10: internal compiler error: in extract_insn, at recog.c:2188

This bug is possibly related to bug 9352, although that one used g++ on a 
different platform.