# RUN: llc -march=amdgcn -run-pass detect-dead-lanes -o - %s | FileCheck %s --- | define void @test0() { ret void } define void @test1() { ret void } define void @test2() { ret void } define void @test3() { ret void } define void @test4() { ret void } define void @test5() { ret void } define void @loop0() { ret void } define void @loop1() { ret void } define void @loop2() { ret void } ... --- # Combined use/def transfer check, the basics. # CHECK-LABEL: name: test0 # CHECK: S_NOP 0, implicit-def %0 # CHECK: S_NOP 0, implicit-def %1 # CHECK: S_NOP 0, implicit-def dead %2 # CHECK: %3 = REG_SEQUENCE %0, {{[0-9]+}}, %1, {{[0-9]+}}, undef %2, {{[0-9]+}} # CHECK: S_NOP 0, implicit %3.sub0 # CHECK: S_NOP 0, implicit %3.sub1 # CHECK: S_NOP 0, implicit undef %3.sub2 # CHECK: %4 = COPY %3.sub0_sub1 # CHECK: %5 = COPY undef %3.sub2_sub3 # CHECK: S_NOP 0, implicit %4.sub0 # CHECK: S_NOP 0, implicit %4.sub1 # CHECK: S_NOP 0, implicit undef %5.sub0 name: test0 registers: - { id: 0, class: sreg_32_xm0 } - { id: 1, class: sreg_32_xm0 } - { id: 2, class: sreg_32_xm0 } - { id: 3, class: sreg_128 } - { id: 4, class: sreg_64 } - { id: 5, class: sreg_64 } body: | bb.0: S_NOP 0, implicit-def %0 S_NOP 0, implicit-def %1 S_NOP 0, implicit-def %2 %3 = REG_SEQUENCE %0, %subreg.sub0, %1, %subreg.sub1, %2, %subreg.sub3 S_NOP 0, implicit %3.sub0 S_NOP 0, implicit %3.sub1 S_NOP 0, implicit %3.sub2 %4 = COPY %3.sub0_sub1 %5 = COPY %3.sub2_sub3 S_NOP 0, implicit %4.sub0 S_NOP 0, implicit %4.sub1 S_NOP 0, implicit %5.sub0 ... --- # Check defined lanes transfer; Includes checking for some special cases like # undef operands or IMPLICIT_DEF definitions. # CHECK-LABEL: name: test1 # CHECK: %0 = REG_SEQUENCE %sgpr0, {{[0-9]+}}, %sgpr0, {{[0-9]+}} # CHECK: %1 = INSERT_SUBREG %0, %sgpr1, {{[0-9]+}} # CHECK: %2 = INSERT_SUBREG %0.sub2_sub3, %sgpr42, {{[0-9]+}} # CHECK: S_NOP 0, implicit %1.sub0 # CHECK: S_NOP 0, implicit undef %1.sub1 # CHECK: S_NOP 0, implicit %1.sub2 # CHECK: S_NOP 0, implicit %1.sub3 # CHECK: S_NOP 0, implicit %2.sub0 # CHECK: S_NOP 0, implicit undef %2.sub1 # CHECK: %3 = IMPLICIT_DEF # CHECK: %4 = INSERT_SUBREG %0, undef %3, {{[0-9]+}} # CHECK: S_NOP 0, implicit undef %4.sub0 # CHECK: S_NOP 0, implicit undef %4.sub1 # CHECK: S_NOP 0, implicit %4.sub2 # CHECK: S_NOP 0, implicit undef %4.sub3 # CHECK: %5 = EXTRACT_SUBREG %0, {{[0-9]+}} # CHECK: %6 = EXTRACT_SUBREG %5, {{[0-9]+}} # CHECK: %7 = EXTRACT_SUBREG %5, {{[0-9]+}} # CHECK: S_NOP 0, implicit %5 # CHECK: S_NOP 0, implicit %6 # CHECK: S_NOP 0, implicit undef %7 # CHECK: %8 = IMPLICIT_DEF # CHECK: %9 = EXTRACT_SUBREG undef %8, {{[0-9]+}} # CHECK: S_NOP 0, implicit undef %9 # CHECK: %10 = EXTRACT_SUBREG undef %0, {{[0-9]+}} # CHECK: S_NOP 0, implicit undef %10 name: test1 registers: - { id: 0, class: sreg_128 } - { id: 1, class: sreg_128 } - { id: 2, class: sreg_64 } - { id: 3, class: sreg_32_xm0 } - { id: 4, class: sreg_128 } - { id: 5, class: sreg_64 } - { id: 6, class: sreg_32_xm0 } - { id: 7, class: sreg_32_xm0 } - { id: 8, class: sreg_64 } - { id: 9, class: sreg_32_xm0 } - { id: 10, class: sreg_128 } body: | bb.0: %0 = REG_SEQUENCE %sgpr0, %subreg.sub0, %sgpr0, %subreg.sub2 %1 = INSERT_SUBREG %0, %sgpr1, %subreg.sub3 %2 = INSERT_SUBREG %0.sub2_sub3, %sgpr42, %subreg.sub0 S_NOP 0, implicit %1.sub0 S_NOP 0, implicit %1.sub1 S_NOP 0, implicit %1.sub2 S_NOP 0, implicit %1.sub3 S_NOP 0, implicit %2.sub0 S_NOP 0, implicit %2.sub1 %3 = IMPLICIT_DEF %4 = INSERT_SUBREG %0, %3, %subreg.sub0 S_NOP 0, implicit %4.sub0 S_NOP 0, implicit %4.sub1 S_NOP 0, implicit %4.sub2 S_NOP 0, implicit %4.sub3 %5 = EXTRACT_SUBREG %0, %subreg.sub0_sub1 %6 = EXTRACT_SUBREG %5, %subreg.sub0 %7 = EXTRACT_SUBREG %5, %subreg.sub1 S_NOP 0, implicit %5 S_NOP 0, implicit %6 S_NOP 0, implicit %7 %8 = IMPLICIT_DEF %9 = EXTRACT_SUBREG %8, %subreg.sub1 S_NOP 0, implicit %9 %10 = EXTRACT_SUBREG undef %0, %subreg.sub2_sub3 S_NOP 0, implicit %10 ... --- # Check used lanes transfer; Includes checking for some special cases like # undef operands. # CHECK-LABEL: name: test2 # CHECK: S_NOP 0, implicit-def dead %0 # CHECK: S_NOP 0, implicit-def %1 # CHECK: S_NOP 0, implicit-def %2 # CHECK: %3 = REG_SEQUENCE undef %0, {{[0-9]+}}, %1, {{[0-9]+}}, %2, {{[0-9]+}} # CHECK: S_NOP 0, implicit %3.sub1 # CHECK: S_NOP 0, implicit %3.sub3 # CHECK: S_NOP 0, implicit-def %4 # CHECK: S_NOP 0, implicit-def dead %5 # CHECK: %6 = REG_SEQUENCE %4, {{[0-9]+}}, undef %5, {{[0-9]+}} # CHECK: S_NOP 0, implicit %6 # CHECK: S_NOP 0, implicit-def dead %7 # CHECK: S_NOP 0, implicit-def %8 # CHECK: %9 = INSERT_SUBREG undef %7, %8, {{[0-9]+}} # CHECK: S_NOP 0, implicit %9.sub2 # CHECK: S_NOP 0, implicit-def %10 # CHECK: S_NOP 0, implicit-def dead %11 # CHECK: %12 = INSERT_SUBREG %10, undef %11, {{[0-9]+}} # CHECK: S_NOP 0, implicit %12.sub3 # CHECK: S_NOP 0, implicit-def %13 # CHECK: S_NOP 0, implicit-def dead %14 # CHECK: %15 = REG_SEQUENCE %13, {{[0-9]+}}, undef %14, {{[0-9]+}} # CHECK: %16 = EXTRACT_SUBREG %15, {{[0-9]+}} # CHECK: S_NOP 0, implicit %16.sub1 name: test2 registers: - { id: 0, class: sreg_32_xm0 } - { id: 1, class: sreg_32_xm0 } - { id: 2, class: sreg_64 } - { id: 3, class: sreg_128 } - { id: 4, class: sreg_32_xm0 } - { id: 5, class: sreg_32_xm0 } - { id: 6, class: sreg_64 } - { id: 7, class: sreg_128 } - { id: 8, class: sreg_64 } - { id: 9, class: sreg_128 } - { id: 10, class: sreg_128 } - { id: 11, class: sreg_64 } - { id: 12, class: sreg_128 } - { id: 13, class: sreg_64 } - { id: 14, class: sreg_64 } - { id: 15, class: sreg_128 } - { id: 16, class: sreg_64 } body: | bb.0: S_NOP 0, implicit-def %0 S_NOP 0, implicit-def %1 S_NOP 0, implicit-def %2 %3 = REG_SEQUENCE %0, %subreg.sub0, %1, %subreg.sub1, %2, %subreg.sub2_sub3 S_NOP 0, implicit %3.sub1 S_NOP 0, implicit %3.sub3 S_NOP 0, implicit-def %4 S_NOP 0, implicit-def %5 %6 = REG_SEQUENCE %4, %subreg.sub0, undef %5, %subreg.sub1 S_NOP 0, implicit %6 S_NOP 0, implicit-def %7 S_NOP 0, implicit-def %8 %9 = INSERT_SUBREG %7, %8, %subreg.sub2_sub3 S_NOP 0, implicit %9.sub2 S_NOP 0, implicit-def %10 S_NOP 0, implicit-def %11 %12 = INSERT_SUBREG %10, %11, %subreg.sub0_sub1 S_NOP 0, implicit %12.sub3 S_NOP 0, implicit-def %13 S_NOP 0, implicit-def %14 %15 = REG_SEQUENCE %13, %subreg.sub0_sub1, %14, %subreg.sub2_sub3 %16 = EXTRACT_SUBREG %15, %subreg.sub0_sub1 S_NOP 0, implicit %16.sub1 ... --- # Check that copies to physregs use all lanes, copies from physregs define all # lanes. So we should not get a dead/undef flag here. # CHECK-LABEL: name: test3 # CHECK: S_NOP 0, implicit-def %0 # CHECK: %vcc = COPY %0 # CHECK: %1 = COPY %vcc # CHECK: S_NOP 0, implicit %1 name: test3 tracksRegLiveness: true registers: - { id: 0, class: sreg_64 } - { id: 1, class: sreg_64 } body: | bb.0: S_NOP 0, implicit-def %0 %vcc = COPY %0 %1 = COPY %vcc S_NOP 0, implicit %1 ... --- # Check that implicit-def/kill do not count as def/uses. # CHECK-LABEL: name: test4 # CHECK: S_NOP 0, implicit-def dead %0 # CHECK: KILL undef %0 # CHECK: %1 = IMPLICIT_DEF # CHECK: S_NOP 0, implicit undef %1 name: test4 tracksRegLiveness: true registers: - { id: 0, class: sreg_64 } - { id: 1, class: sreg_64 } body: | bb.0: S_NOP 0, implicit-def %0 KILL %0 %1 = IMPLICIT_DEF S_NOP 0, implicit %1 ... --- # Check that unused inputs are marked as undef, even if the vreg itself is # used. # CHECK-LABEL: name: test5 # CHECK: S_NOP 0, implicit-def %0 # CHECK: %1 = REG_SEQUENCE undef %0, {{[0-9]+}}, %0, {{[0-9]+}} # CHECK: S_NOP 0, implicit %1.sub1 name: test5 tracksRegLiveness: true registers: - { id: 0, class: sreg_32_xm0 } - { id: 1, class: sreg_64 } body: | bb.0: S_NOP 0, implicit-def %0 %1 = REG_SEQUENCE %0, %subreg.sub0, %0, %subreg.sub1 S_NOP 0, implicit %1.sub1 ... --- # Check "optimistic" dataflow fixpoint in phi-loops. # CHECK-LABEL: name: loop0 # CHECK: bb.0: # CHECK: S_NOP 0, implicit-def %0 # CHECK: S_NOP 0, implicit-def dead %1 # CHECK: S_NOP 0, implicit-def dead %2 # CHECK: %3 = REG_SEQUENCE %0, {{[0-9]+}}, undef %1, {{[0-9]+}}, undef %2, {{[0-9]+}} # CHECK: bb.1: # CHECK: %4 = PHI %3, %bb.0, %5, %bb.1 # CHECK: bb.2: # CHECK: S_NOP 0, implicit %4.sub0 # CHECK: S_NOP 0, implicit undef %4.sub3 name: loop0 tracksRegLiveness: true registers: - { id: 0, class: sreg_32_xm0 } - { id: 1, class: sreg_32_xm0 } - { id: 2, class: sreg_32_xm0 } - { id: 3, class: sreg_128 } - { id: 4, class: sreg_128 } - { id: 5, class: sreg_128 } body: | bb.0: successors: %bb.1 S_NOP 0, implicit-def %0 S_NOP 0, implicit-def %1 S_NOP 0, implicit-def %2 %3 = REG_SEQUENCE %0, %subreg.sub0, %1, %subreg.sub1, %2, %subreg.sub2 S_BRANCH %bb.1 bb.1: successors: %bb.1, %bb.2 %4 = PHI %3, %bb.0, %5, %bb.1 ; let's swiffle some lanes around for fun... %5 = REG_SEQUENCE %4.sub0, %subreg.sub0, %4.sub2, %subreg.sub1, %4.sub1, %subreg.sub2, %4.sub3, %subreg.sub3 S_CBRANCH_VCCNZ %bb.1, implicit undef %vcc S_BRANCH %bb.2 bb.2: S_NOP 0, implicit %4.sub0 S_NOP 0, implicit %4.sub3 ... --- # Check a loop that needs to be traversed multiple times to reach the fixpoint # for the used lanes. The example reads sub3 lane at the end, however with each # loop iteration we should get 1 more lane marked as we cycles the sublanes # along. Sublanes sub0, sub1 and sub3 are rotate in the loop so only sub2 # should be dead. # CHECK-LABEL: name: loop1 # CHECK: bb.0: # CHECK: S_NOP 0, implicit-def %0 # CHECK: S_NOP 0, implicit-def %1 # CHECK: S_NOP 0, implicit-def dead %2 # CHECK: S_NOP 0, implicit-def %3 # CHECK: %4 = REG_SEQUENCE %0, {{[0-9]+}}, %1, {{[0-9]+}}, undef %2, {{[0-9]+}}, %3, {{[0-9]+}} # CHECK: bb.1: # CHECK: %5 = PHI %4, %bb.0, %6, %bb.1 # CHECK: %6 = REG_SEQUENCE %5.sub1, {{[0-9]+}}, %5.sub3, {{[0-9]+}}, undef %5.sub2, {{[0-9]+}}, %5.sub0, {{[0-9]+}} # CHECK: bb.2: # CHECK: S_NOP 0, implicit %6.sub3 name: loop1 tracksRegLiveness: true registers: - { id: 0, class: sreg_32_xm0 } - { id: 1, class: sreg_32_xm0 } - { id: 2, class: sreg_32_xm0 } - { id: 3, class: sreg_32_xm0 } - { id: 4, class: sreg_128 } - { id: 5, class: sreg_128 } - { id: 6, class: sreg_128 } body: | bb.0: successors: %bb.1 S_NOP 0, implicit-def %0 S_NOP 0, implicit-def %1 S_NOP 0, implicit-def dead %2 S_NOP 0, implicit-def %3 %4 = REG_SEQUENCE %0, %subreg.sub0, %1, %subreg.sub1, %2, %subreg.sub2, %3, %subreg.sub3 S_BRANCH %bb.1 bb.1: successors: %bb.1, %bb.2 %5 = PHI %4, %bb.0, %6, %bb.1 ; rotate lanes, but skip sub2 lane... %6 = REG_SEQUENCE %5.sub1, %subreg.sub0, %5.sub3, %subreg.sub1, %5.sub2, %subreg.sub2, %5.sub0, %subreg.sub3 S_CBRANCH_VCCNZ %bb.1, implicit undef %vcc S_BRANCH %bb.2 bb.2: S_NOP 0, implicit %6.sub3 ... --- # Similar to loop1 test, but check for fixpoint of defined lanes. # Lanes are rotate between sub0, sub2, sub3 so only sub1 should be dead/undef. # CHECK-LABEL: name: loop2 # CHECK: bb.0: # CHECK: S_NOP 0, implicit-def %0 # CHECK: %1 = REG_SEQUENCE %0, {{[0-9]+}} # CHECK: bb.1: # CHECK: %2 = PHI %1, %bb.0, %3, %bb.1 # CHECK: %3 = REG_SEQUENCE %2.sub3, {{[0-9]+}}, undef %2.sub1, {{[0-9]+}}, %2.sub0, {{[0-9]+}}, %2.sub2, {{[0-9]+}} # CHECK: bb.2: # CHECK: S_NOP 0, implicit %2.sub0 # CHECK: S_NOP 0, implicit undef %2.sub1 # CHECK: S_NOP 0, implicit %2.sub2 # CHECK: S_NOP 0, implicit %2.sub3 name: loop2 tracksRegLiveness: true registers: - { id: 0, class: sreg_32_xm0 } - { id: 1, class: sreg_128 } - { id: 2, class: sreg_128 } - { id: 3, class: sreg_128 } body: | bb.0: successors: %bb.1 S_NOP 0, implicit-def %0 %1 = REG_SEQUENCE %0, %subreg.sub0 S_BRANCH %bb.1 bb.1: successors: %bb.1, %bb.2 %2 = PHI %1, %bb.0, %3, %bb.1 ; rotate subreg lanes, skipping sub1 %3 = REG_SEQUENCE %2.sub3, %subreg.sub0, %2.sub1, %subreg.sub1, %2.sub0, %subreg.sub2, %2.sub2, %subreg.sub3 S_CBRANCH_VCCNZ %bb.1, implicit undef %vcc S_BRANCH %bb.2 bb.2: S_NOP 0, implicit %2.sub0 S_NOP 0, implicit undef %2.sub1 S_NOP 0, implicit %2.sub2 S_NOP 0, implicit %2.sub3 ...