[PATCH,ARM][4/n] Add negdi_extend patterns
Greta Yorsh
greta.yorsh@arm.com
Mon Feb 18 18:41:00 GMT 2013
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.Yorsh@arm.com>
* config/arm/arm.md (negdi_extendsidi): New pattern.
(negdi_zero_extendsidi): Likewise.
gcc/testsuite
2013-01-10 Greta Yorsh <Greta.Yorsh@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.
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