Reapply "[llvm-exegesis] Implement the loop repetition mode for AArch64" (#155423) #155589
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…64" (llvm#155423) This includes two minor fixes: - "Codegen" has been added to the LLVM_LINK_COMPONENTS for AArch64 to prevent a link error, - the test case has been made less strict or fragile by not checking the addresses.
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| @llvm/pr-subscribers-tools-llvm-exegesis Author: Sjoerd Meijer (sjoerdmeijer) ChangesThis includes two minor fixes:
Full diff: https://github.com/llvm/llvm-project/pull/155589.diff 3 Files Affected:
diff --git a/llvm/test/tools/llvm-exegesis/AArch64/loop-register.s b/llvm/test/tools/llvm-exegesis/AArch64/loop-register.s new file mode 100644 index 0000000000000..62040b26c8faf --- /dev/null +++ b/llvm/test/tools/llvm-exegesis/AArch64/loop-register.s @@ -0,0 +1,17 @@ +REQUIRES: aarch64-registered-target, asserts + +RUN: llvm-exegesis -mcpu=neoverse-v2 --use-dummy-perf-counters --mode=latency --debug-only=print-gen-assembly --opcode-name=ADDVv4i16v -repetition-mode=loop 2>&1 | FileCheck %s + +CHECK: str x19, [sp, #-16]! +CHECK-NEXT: movi d[[REG:[0-9]+]], #0000000000000000 +CHECK-NEXT: mov x19, #10000 +CHECK-NEXT: nop +CHECK-NEXT: nop +CHECK-NEXT: nop +CHECK-NEXT: nop +CHECK-NEXT: nop +CHECK-NEXT: addv h[[REG]], v[[REG]].4h +CHECK-NEXT: subs x19, x19, #1 +CHECK-NEXT: b.ne #-8 +CHECK-NEXT: ldr x19, [sp], #16 +CHECK-NEXT: ret diff --git a/llvm/tools/llvm-exegesis/lib/AArch64/CMakeLists.txt b/llvm/tools/llvm-exegesis/lib/AArch64/CMakeLists.txt index 42f8fd30ac2bb..091215c18632d 100644 --- a/llvm/tools/llvm-exegesis/lib/AArch64/CMakeLists.txt +++ b/llvm/tools/llvm-exegesis/lib/AArch64/CMakeLists.txt @@ -5,6 +5,7 @@ include_directories( set(LLVM_LINK_COMPONENTS AArch64 + CodeGen CodeGenTypes Core Exegesis diff --git a/llvm/tools/llvm-exegesis/lib/AArch64/Target.cpp b/llvm/tools/llvm-exegesis/lib/AArch64/Target.cpp index 3a0021e3c132d..c4ad9ae201d4e 100644 --- a/llvm/tools/llvm-exegesis/lib/AArch64/Target.cpp +++ b/llvm/tools/llvm-exegesis/lib/AArch64/Target.cpp @@ -8,6 +8,7 @@ #include "../Target.h" #include "AArch64.h" #include "AArch64RegisterInfo.h" +#include "llvm/CodeGen/MachineInstrBuilder.h" #if defined(__aarch64__) && defined(__linux__) #include <sys/prctl.h> // For PR_PAC_* constants @@ -109,6 +110,10 @@ static MCInst loadFPImmediate(MCRegister Reg, unsigned RegBitWidth, namespace { +// Use X19 as the loop counter register since it's a callee-saved register +// that's available for temporary use. +constexpr const MCPhysReg kDefaultLoopCounterReg = AArch64::X19; + class ExegesisAArch64Target : public ExegesisTarget { public: ExegesisAArch64Target() @@ -141,6 +146,31 @@ class ExegesisAArch64Target : public ExegesisTarget { errs() << "setRegTo is not implemented, results will be unreliable\n"; return {}; } + MCRegister getDefaultLoopCounterRegister(const Triple &) const override { + return kDefaultLoopCounterReg; + } + + void decrementLoopCounterAndJump(MachineBasicBlock &MBB, + MachineBasicBlock &TargetMBB, + const MCInstrInfo &MII, + MCRegister LoopRegister) const override { + // subs LoopRegister, LoopRegister, #1 + BuildMI(&MBB, DebugLoc(), MII.get(AArch64::SUBSXri)) + .addDef(LoopRegister) + .addUse(LoopRegister) + .addImm(1) // Subtract 1 + .addImm(0); // No shift amount + // b.ne TargetMBB + BuildMI(&MBB, DebugLoc(), MII.get(AArch64::Bcc)) + .addImm(AArch64CC::NE) + .addMBB(&TargetMBB); + } + + // Registers that should not be selected for use in snippets. + const MCPhysReg UnavailableRegisters[1] = {kDefaultLoopCounterReg}; + ArrayRef<MCPhysReg> getUnavailableRegisters() const override { + return UnavailableRegisters; + } bool matchesArch(Triple::ArchType Arch) const override { return Arch == Triple::aarch64 || Arch == Triple::aarch64_be; |
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| LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/59/builds/23307 Here is the relevant piece of the build log for the reference |
Collaborator
| LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/65/builds/21839 Here is the relevant piece of the build log for the reference |
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This includes two minor fixes: