[Bug target/82034] SMMLAR pattern not detected on ARMv7-M

[rearnsha at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82034

Richard Earnshaw <rearnsha at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |RESOLVED
         Resolution|---                         |WORKSFORME

--- Comment #4 from Richard Earnshaw <rearnsha at gcc dot gnu.org> ---
Your example command line has no optimization flags on it, so it's not
surprising that you don't see the idiom reduced.  With gcc-7 and -O3 I get:

        sub     sp, sp, #16
        movs    r1, #1
        movs    r2, #2
        movs    r3, #3
        str     r1, [sp, #4]
        str     r2, [sp, #8]
        str     r3, [sp, #12]
        ldr     r0, [sp, #4]
        ldr     r3, [sp, #8]
        ldr     r2, [sp, #12]
        .syntax unified
@ 15 "test.c" 1
        smmlar r3, r3, r2, r0
@ 0 "" 2
        .thumb
        .syntax unified
        add     sp, sp, #16
        @ sp needed
        bx      lr