| # RUN: llc -march=hexagon -run-pass branch-folder %s -o - -verify-machineinstrs | FileCheck %s |
| |
| # Branch folding will perform tail merging of bb.1 and bb.2, and bb.2 will |
| # become the common tail. The use of R0 in bb.2 is <undef> while the |
| # corresponding use in bb.1 is not. The common tail will have the <undef> |
| # flag removed, which will cause R0 to become a live-in to bb.2. The problem |
| # is that R0 is not live-out from all predecessors of bb.2, namely is not |
| # live-out from bb.0. To remedy that, the branch folder should add an |
| # IMPLICIT_DEF to that block. |
| |
| # CHECK-LABEL: name: func0 |
| # CHECK-LABEL: bb.0: |
| # CHECK: $r0 = IMPLICIT_DEF |
| # CHECK-LABEL: bb.1: |
| # CHECK-LABEL: bb.2: |
| # CHECK: liveins: $r0 |
| # CHECK: PS_storerhabs 0, $r0 |
| # CHECK: PS_jmpret |
| |
| --- |
| name: func0 |
| tracksRegLiveness: true |
| |
| body: | |
| bb.0: |
| liveins: $r31 |
| successors: %bb.1, %bb.2 |
| J2_jumpt undef $p0, %bb.2, implicit-def $pc |
| J2_jump %bb.1, implicit-def $pc |
| |
| bb.1: |
| liveins: $r31 |
| successors: %bb.3 |
| $r0 = L2_loadruh_io undef $r1, 0 |
| PS_storerhabs 0, killed $r0 |
| J2_jump %bb.3, implicit-def $pc |
| |
| bb.2: |
| liveins: $r31 |
| successors: %bb.3 |
| PS_storerhabs 0, undef $r0 |
| J2_jump %bb.3, implicit-def $pc |
| |
| bb.3: |
| liveins: $r31 |
| PS_jmpret killed $r31, implicit-def $pc |
| ... |
| --- |
| # CHECK-LABEL: name: func1 |
| # CHECK-LABEL: bb.1: |
| # CHECK: $r0 = IMPLICIT_DEF |
| # CHECK-LABEL: bb.2: |
| # CHECK-LABEL: bb.3: |
| # CHECK: liveins: $r0 |
| # CHECK: PS_storerhabs 0, killed $r0 |
| # CHECK: PS_jmpret |
| |
| name: func1 |
| tracksRegLiveness: true |
| |
| body: | |
| bb.0: |
| liveins: $r31 |
| successors: %bb.1, %bb.2 |
| J2_jumpt undef $p0, %bb.2, implicit-def $pc |
| J2_jump %bb.1, implicit-def $pc |
| |
| bb.1: |
| liveins: $r31 |
| successors: %bb.3 |
| $r1 = A2_tfrsi 1 |
| PS_storerhabs 0, undef $r0 |
| $r0 = A2_tfrsi 1 |
| J2_jump %bb.3, implicit-def $pc |
| |
| bb.2: |
| liveins: $r31 |
| successors: %bb.3 |
| $r0 = L2_loadruh_io undef $r1, 0 |
| PS_storerhabs 0, killed $r0 |
| $r0 = A2_tfrsi 1 |
| J2_jump %bb.3, implicit-def $pc |
| |
| bb.3: |
| liveins: $r31 |
| PS_jmpret killed $r31, implicit undef $r0, implicit-def $pc |
| ... |
