On Mon, Feb 18, 2013 at 6:40 PM, Greta Yorsh <greta.yo...@arm.com> wrote: > This patch adds patterns to handle negation of an extended 32-bit value more > efficiently. > > For example, > > (set (reg:DI r0) (neg:DI (sign_extend:DI (reg:SI r0))) > > The compiler currently generates > mov r1, r0, asr #31 > rsbs r0, r0, #0 > rsc r1, r1, #0 > and after the patch it generates: > rsb r0, r0, #0 > mov r1, r0, asr #31 > > (set (reg:DI r0) (neg:DI (zero_extend:DI (reg:SI r0))) > > The compiler currently generates > mov r1, #0 > rsbs r0, r0, #0 > rsc r1, r1, #0 > and after the patch it generates: > rsbs r0, r0, #0 > sbc r1, r1, r1 > > The following examples are not affected by the patch: > > (set (reg:DI r0) (sign_extend:DI (neg:SI (reg:SI r0))) > rsb r0, r0, #0 > mov r1, r0, asr #31 > > (set (reg:DI r0) (zero_extend:DI (neg:SI (reg:SI r0))) > rsb r0, r0, #0 > mov r1, #0 > > The patch also adds the appropriate test cases. > > gcc/ > > 2013-01-10 Greta Yorsh <greta.yo...@arm.com> > > * config/arm/arm.md (negdi_extendsidi): New pattern. > (negdi_zero_extendsidi): Likewise. > > gcc/testsuite > > 2013-01-10 Greta Yorsh <greta.yo...@arm.com> > > * gcc.target/arm/negdi-1.c: New test. > * gcc.target/arm/negdi-2.c: Likewise. > * gcc.target/arm/negdi-3.c: Likewise. > * gcc.target/arm/negdi-4.c: Likewise.
Ok. Ramana
