# RUN: llc -march=hexagon -run-pass hwloops %s -o - | FileCheck %s # Normally, if the registers holding the induction variable's bounds # are redefined inside of the loop's body, the loop cannot be converted # to a hardware loop. However, if the redefining instruction is actually # loading an immediate value into the register, this conversion is both # possible and legal (since the immediate itself will be used in the # loop setup in the preheader). # CHECK: [[R0:%[0-9]+]]:intregs = A2_tfrsi 1920 # CHECK: J2_loop0r %bb.1, [[R0]] # # CHECK: bb.1.b1 (address-taken): # CHECK: ENDLOOP0 %bb.1 --- | define void @fred() { b0: br label %b1 b1: br label %b2 b2: ret void } ... --- name: fred tracksRegLiveness: true registers: - { id: 0, class: intregs } - { id: 1, class: intregs } - { id: 2, class: intregs } - { id: 3, class: intregs } - { id: 4, class: intregs } - { id: 5, class: intregs } - { id: 6, class: intregs } - { id: 7, class: intregs } - { id: 8, class: predregs } body: | bb.0.b0: liveins: $r0 successors: %bb.1 %0 = A2_tfrsi 0 %1 = A2_tfrsi 0 %2 = COPY $r0 bb.1.b1: successors: %bb.1, %bb.2 %3 = PHI %0, %bb.0, %6, %bb.1 %4 = PHI %1, %bb.0, %5, %bb.1 S4_storerh_rr %2, %4, 0, %3 %5 = A2_addi %4, 2 %6 = A2_addi %3, 1 ; This definition of %7 should not prevent conversion to hardware loop. %7 = A2_tfrsi 3840 %8 = C2_cmpeq %5, %7 J2_jumpf %8, %bb.1, implicit-def $pc J2_jump %bb.2, implicit-def $pc bb.2.b2: ...