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From: "abnikant dot singh at atmel dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/33970] Missed optimization using unsigned char loop variable Date: Mon, 13 Sep 2010 12:09:00 -0000 [thread overview] Message-ID: <20100913120912.12626.qmail@sourceware.org> (raw) In-Reply-To: <bug-33970-15294@http.gcc.gnu.org/bugzilla/> ------- Comment #12 from abnikant dot singh at atmel dot com 2010-09-13 12:09 ------- I have verified the attached test case and test case with other comments and found the code generated is correct i.e. the variable is not promoted to integer in gcc-4.3.3, gcc-4.4.3, gcc-4.5.0 and also the latest head. The assembly for the following piece of code: int sub2(unsigned char); // external function void foo(void) { unsigned char x; for(x=0;x<128; x++) { sub2(x); //x is becomes a int (16bit) // sub2(x+1); //x is char (8bit) } } in gcc-4.3.3 is: foo: push r17 /* prologue: function */ /* frame size = 0 */ ldi r17,lo8(0) .L2: mov r24,r17 rcall sub2 subi r17,lo8(-(1)) cpi r17,lo8(-128) brne .L2 /* epilogue start */ pop r17 ret .size foo, .-foo -- abnikant dot singh at atmel dot com changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |abnikant dot singh at atmel | |dot com http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33970
next prev parent reply other threads:[~2010-09-13 12:09 UTC|newest] Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top 2007-11-01 13:44 [Bug c/33970] New: " henning dot m at insightbb dot com 2007-11-01 14:10 ` [Bug c/33970] " rguenth at gcc dot gnu dot org 2007-11-01 17:09 ` [Bug middle-end/33970] " pinskia at gcc dot gnu dot org 2007-11-01 17:28 ` eweddington at cso dot atmel dot com 2007-11-01 17:45 ` eweddington at cso dot atmel dot com 2007-11-01 17:47 ` eweddington at cso dot atmel dot com 2007-11-01 21:26 ` henning dot m at insightbb dot com 2007-11-04 23:28 ` eweddington at cso dot atmel dot com 2007-11-04 23:28 ` eweddington at cso dot atmel dot com 2007-11-05 22:48 ` wvangulik at xs4all dot nl 2007-11-06 12:37 ` henning dot m at insightbb dot com 2007-11-06 19:35 ` wvangulik at xs4all dot nl 2007-11-06 21:01 ` wvangulik at xs4all dot nl 2010-09-13 12:09 ` abnikant dot singh at atmel dot com [this message] [not found] <bug-33970-4@http.gcc.gnu.org/bugzilla/> 2011-07-20 17:48 ` gjl at gcc dot gnu.org
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