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llvm-project/llvm/test/CodeGen/X86/late-remat-update.mir

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[RegisterCoalescer] Delay live interval update work until the rematerialization for all the uses from the same def is done. We run into a compile time problem with flex generated code combined with `-fno-jump-tables`. The cause is that machineLICM hoists a lot of invariants outside of a big loop, and drastically increases the compile time in global register splitting and copy coalescing. https://reviews.llvm.org/D49353 relieves the problem in global splitting. This patch is to handle the problem in copy coalescing. About the situation where the problem in copy coalescing happens. After machineLICM, we have several defs outside of a big loop with hundreds or thousands of uses inside the loop. Rematerialization in copy coalescing happens for each use and everytime rematerialization is done, shrinkToUses will be called to update the huge live interval. Because we have 'n' uses for a def, and each live interval update will have at least 'n' complexity, the total update work is n^2. To fix the problem, we try to do the live interval update work in a collective way. If a def has many copylike uses larger than a threshold, each time rematerialization is done for one of those uses, we won't do the live interval update in time but delay that work until rematerialization for all those uses are completed, so we only have to do the live interval update work once. Delaying the live interval update could potentially change the copy coalescing result, so we hope to limit that change to those defs with many (like above a hundred) copylike uses, and the cutoff can be adjusted by the option -mllvm -late-remat-update-threshold=xxx. Differential Revision: https://reviews.llvm.org/D49519 llvm-svn: 339035
2018-08-07 01:30:45 +08:00
# REQUIRES: asserts
# RUN: llc -mtriple=x86_64-- -run-pass=simple-register-coalescing -late-remat-update-threshold=1 -stats %s -o /dev/null 2>&1 | FileCheck %s
# Check the test will rematerialize for three copies, but will call shrinkToUses
# only once to update live range because of late rematerialization update.
# CHECK: 3 regalloc - Number of instructions re-materialized
# CHECK: 1 regalloc - Number of shrinkToUses called
--- |
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
; Function Attrs: noreturn uwtable
define void @_Z3fooi(i32 %value) local_unnamed_addr #0 {
entry:
br label %do.body
do.body: ; preds = %do.body, %sw.bb2, %entry
tail call void asm sideeffect "", "~{r10},~{r11},~{r12},~{r13},~{r14},~{r15},~{dirflag},~{fpsr},~{flags}"() #2, !srcloc !3
switch i32 %value, label %do.body [
i32 0, label %sw.bb
i32 1, label %sw.bb1
i32 2, label %sw.bb2
]
sw.bb: ; preds = %do.body
tail call void @_Z3gooi(i32 2122)
br label %sw.bb1
sw.bb1: ; preds = %sw.bb, %do.body
tail call void @_Z3gooi(i32 2122)
br label %sw.bb2
sw.bb2: ; preds = %sw.bb1, %do.body
tail call void @_Z3gooi(i32 2122)
br label %do.body
}
declare void @_Z3gooi(i32) local_unnamed_addr #1
; Function Attrs: nounwind
declare void @llvm.stackprotector(i8*, i8**) #2
attributes #0 = { noreturn uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #2 = { nounwind }
!llvm.module.flags = !{!0, !1}
!llvm.ident = !{!2}
!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 7, !"PIC Level", i32 2}
!2 = !{!"clang version 7.0.0 (trunk 335057)"}
!3 = !{i32 82}
...
---
name: _Z3fooi
alignment: 4
tracksRegLiveness: true
registers:
- { id: 0, class: gr32 }
- { id: 1, class: gr32 }
- { id: 2, class: gr32 }
- { id: 3, class: gr32 }
- { id: 4, class: gr32 }
- { id: 5, class: gr32 }
liveins:
- { reg: '$edi', virtual-reg: '%0' }
frameInfo:
hasCalls: true
body: |
bb.0.entry:
liveins: $edi
%0:gr32 = COPY killed $edi
%5:gr32 = MOV32ri 2122
bb.1.do.body:
successors: %bb.6(0x15555555), %bb.2(0x6aaaaaab)
INLINEASM &"", 1, 12, implicit-def dead early-clobber $r10, 12, implicit-def dead early-clobber $r11, 12, implicit-def dead early-clobber $r12, 12, implicit-def dead early-clobber $r13, 12, implicit-def dead early-clobber $r14, 12, implicit-def dead early-clobber $r15, 12, implicit-def dead early-clobber $eflags, !3
CMP32ri8 %0, 2, implicit-def $eflags
[X86] Merge the different Jcc instructions for each condition code into single instructions that store the condition code as an operand. Summary: This avoids needing an isel pattern for each condition code. And it removes translation switches for converting between Jcc instructions and condition codes. Now the printer, encoder and disassembler take care of converting the immediate. We use InstAliases to handle the assembly matching. But we print using the asm string in the instruction definition. The instruction itself is marked IsCodeGenOnly=1 to hide it from the assembly parser. Reviewers: spatel, lebedev.ri, courbet, gchatelet, RKSimon Reviewed By: RKSimon Subscribers: MatzeB, qcolombet, eraman, hiraditya, arphaman, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D60228 llvm-svn: 357802
2019-04-06 03:28:09 +08:00
JCC_1 %bb.6, 4, implicit killed $eflags
[RegisterCoalescer] Delay live interval update work until the rematerialization for all the uses from the same def is done. We run into a compile time problem with flex generated code combined with `-fno-jump-tables`. The cause is that machineLICM hoists a lot of invariants outside of a big loop, and drastically increases the compile time in global register splitting and copy coalescing. https://reviews.llvm.org/D49353 relieves the problem in global splitting. This patch is to handle the problem in copy coalescing. About the situation where the problem in copy coalescing happens. After machineLICM, we have several defs outside of a big loop with hundreds or thousands of uses inside the loop. Rematerialization in copy coalescing happens for each use and everytime rematerialization is done, shrinkToUses will be called to update the huge live interval. Because we have 'n' uses for a def, and each live interval update will have at least 'n' complexity, the total update work is n^2. To fix the problem, we try to do the live interval update work in a collective way. If a def has many copylike uses larger than a threshold, each time rematerialization is done for one of those uses, we won't do the live interval update in time but delay that work until rematerialization for all those uses are completed, so we only have to do the live interval update work once. Delaying the live interval update could potentially change the copy coalescing result, so we hope to limit that change to those defs with many (like above a hundred) copylike uses, and the cutoff can be adjusted by the option -mllvm -late-remat-update-threshold=xxx. Differential Revision: https://reviews.llvm.org/D49519 llvm-svn: 339035
2018-08-07 01:30:45 +08:00
JMP_1 %bb.2
bb.2.do.body:
successors: %bb.5(0x19999999), %bb.3(0x66666667)
CMP32ri8 %0, 1, implicit-def $eflags
[X86] Merge the different Jcc instructions for each condition code into single instructions that store the condition code as an operand. Summary: This avoids needing an isel pattern for each condition code. And it removes translation switches for converting between Jcc instructions and condition codes. Now the printer, encoder and disassembler take care of converting the immediate. We use InstAliases to handle the assembly matching. But we print using the asm string in the instruction definition. The instruction itself is marked IsCodeGenOnly=1 to hide it from the assembly parser. Reviewers: spatel, lebedev.ri, courbet, gchatelet, RKSimon Reviewed By: RKSimon Subscribers: MatzeB, qcolombet, eraman, hiraditya, arphaman, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D60228 llvm-svn: 357802
2019-04-06 03:28:09 +08:00
JCC_1 %bb.5, 4, implicit killed $eflags
[RegisterCoalescer] Delay live interval update work until the rematerialization for all the uses from the same def is done. We run into a compile time problem with flex generated code combined with `-fno-jump-tables`. The cause is that machineLICM hoists a lot of invariants outside of a big loop, and drastically increases the compile time in global register splitting and copy coalescing. https://reviews.llvm.org/D49353 relieves the problem in global splitting. This patch is to handle the problem in copy coalescing. About the situation where the problem in copy coalescing happens. After machineLICM, we have several defs outside of a big loop with hundreds or thousands of uses inside the loop. Rematerialization in copy coalescing happens for each use and everytime rematerialization is done, shrinkToUses will be called to update the huge live interval. Because we have 'n' uses for a def, and each live interval update will have at least 'n' complexity, the total update work is n^2. To fix the problem, we try to do the live interval update work in a collective way. If a def has many copylike uses larger than a threshold, each time rematerialization is done for one of those uses, we won't do the live interval update in time but delay that work until rematerialization for all those uses are completed, so we only have to do the live interval update work once. Delaying the live interval update could potentially change the copy coalescing result, so we hope to limit that change to those defs with many (like above a hundred) copylike uses, and the cutoff can be adjusted by the option -mllvm -late-remat-update-threshold=xxx. Differential Revision: https://reviews.llvm.org/D49519 llvm-svn: 339035
2018-08-07 01:30:45 +08:00
JMP_1 %bb.3
bb.3.do.body:
successors: %bb.4(0x20000000), %bb.1(0x60000000)
TEST32rr %0, %0, implicit-def $eflags
[X86] Merge the different Jcc instructions for each condition code into single instructions that store the condition code as an operand. Summary: This avoids needing an isel pattern for each condition code. And it removes translation switches for converting between Jcc instructions and condition codes. Now the printer, encoder and disassembler take care of converting the immediate. We use InstAliases to handle the assembly matching. But we print using the asm string in the instruction definition. The instruction itself is marked IsCodeGenOnly=1 to hide it from the assembly parser. Reviewers: spatel, lebedev.ri, courbet, gchatelet, RKSimon Reviewed By: RKSimon Subscribers: MatzeB, qcolombet, eraman, hiraditya, arphaman, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D60228 llvm-svn: 357802
2019-04-06 03:28:09 +08:00
JCC_1 %bb.1, 5, implicit killed $eflags
[RegisterCoalescer] Delay live interval update work until the rematerialization for all the uses from the same def is done. We run into a compile time problem with flex generated code combined with `-fno-jump-tables`. The cause is that machineLICM hoists a lot of invariants outside of a big loop, and drastically increases the compile time in global register splitting and copy coalescing. https://reviews.llvm.org/D49353 relieves the problem in global splitting. This patch is to handle the problem in copy coalescing. About the situation where the problem in copy coalescing happens. After machineLICM, we have several defs outside of a big loop with hundreds or thousands of uses inside the loop. Rematerialization in copy coalescing happens for each use and everytime rematerialization is done, shrinkToUses will be called to update the huge live interval. Because we have 'n' uses for a def, and each live interval update will have at least 'n' complexity, the total update work is n^2. To fix the problem, we try to do the live interval update work in a collective way. If a def has many copylike uses larger than a threshold, each time rematerialization is done for one of those uses, we won't do the live interval update in time but delay that work until rematerialization for all those uses are completed, so we only have to do the live interval update work once. Delaying the live interval update could potentially change the copy coalescing result, so we hope to limit that change to those defs with many (like above a hundred) copylike uses, and the cutoff can be adjusted by the option -mllvm -late-remat-update-threshold=xxx. Differential Revision: https://reviews.llvm.org/D49519 llvm-svn: 339035
2018-08-07 01:30:45 +08:00
JMP_1 %bb.4
bb.4.sw.bb:
ADJCALLSTACKDOWN64 0, 0, 0, implicit-def dead $rsp, implicit-def dead $eflags, implicit-def dead $ssp, implicit $rsp, implicit $ssp
$edi = COPY %5
CALL64pcrel32 @_Z3gooi, csr_64, implicit $rsp, implicit $ssp, implicit killed $edi, implicit-def $rsp, implicit-def $ssp
ADJCALLSTACKUP64 0, 0, implicit-def dead $rsp, implicit-def dead $eflags, implicit-def dead $ssp, implicit $rsp, implicit $ssp
bb.5.sw.bb1:
ADJCALLSTACKDOWN64 0, 0, 0, implicit-def dead $rsp, implicit-def dead $eflags, implicit-def dead $ssp, implicit $rsp, implicit $ssp
$edi = COPY %5
CALL64pcrel32 @_Z3gooi, csr_64, implicit $rsp, implicit $ssp, implicit killed $edi, implicit-def $rsp, implicit-def $ssp
ADJCALLSTACKUP64 0, 0, implicit-def dead $rsp, implicit-def dead $eflags, implicit-def dead $ssp, implicit $rsp, implicit $ssp
bb.6.sw.bb2:
ADJCALLSTACKDOWN64 0, 0, 0, implicit-def dead $rsp, implicit-def dead $eflags, implicit-def dead $ssp, implicit $rsp, implicit $ssp
$edi = COPY %5
CALL64pcrel32 @_Z3gooi, csr_64, implicit $rsp, implicit $ssp, implicit killed $edi, implicit-def $rsp, implicit-def $ssp
ADJCALLSTACKUP64 0, 0, implicit-def dead $rsp, implicit-def dead $eflags, implicit-def dead $ssp, implicit $rsp, implicit $ssp
JMP_1 %bb.1
...