[llvm] c40ef64 - [Greedy RegAlloc] Add a test for single block split with statepoint uses.
Serguei Katkov via llvm-commits
llvm-commits at lists.llvm.org
Mon Nov 7 00:04:17 PST 2022
Author: Serguei Katkov
Date: 2022-11-07T14:53:09+07:00
New Revision: c40ef64462eeac9bafc28512dfaae55475016676
URL: https://github.com/llvm/llvm-project/commit/c40ef64462eeac9bafc28512dfaae55475016676
DIFF: https://github.com/llvm/llvm-project/commit/c40ef64462eeac9bafc28512dfaae55475016676.diff
LOG: [Greedy RegAlloc] Add a test for single block split with statepoint uses.
The test shows redundant usage of callee saved register in case
basic block has only one non-statepoint use.
Added:
llvm/test/CodeGen/X86/statepoint-split-single-block.ll
Modified:
Removed:
################################################################################
diff --git a/llvm/test/CodeGen/X86/statepoint-split-single-block.ll b/llvm/test/CodeGen/X86/statepoint-split-single-block.ll
new file mode 100644
index 0000000000000..61368d3101ee6
--- /dev/null
+++ b/llvm/test/CodeGen/X86/statepoint-split-single-block.ll
@@ -0,0 +1,81 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -max-registers-for-gc-values=256 -use-registers-for-deopt-values=true -code-model=large -fixup-allow-gcptr-in-csr=true < %s | FileCheck %s
+
+; The test checks that Greedy register allocator should not split single basic block
+; if it has only one non-statepoint use. Otherwise we may a redundant register usage.
+
+target datalayout = "e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-win64"
+
+define ptr addrspace(1) @foo(ptr addrspace(1) %arg) gc "statepoint-example" {
+; CHECK-LABEL: foo:
+; CHECK: # %bb.0: # %entry
+; CHECK-NEXT: pushq %rbp
+; CHECK-NEXT: .cfi_def_cfa_offset 16
+; CHECK-NEXT: pushq %r15
+; CHECK-NEXT: .cfi_def_cfa_offset 24
+; CHECK-NEXT: pushq %r14
+; CHECK-NEXT: .cfi_def_cfa_offset 32
+; CHECK-NEXT: pushq %r13
+; CHECK-NEXT: .cfi_def_cfa_offset 40
+; CHECK-NEXT: pushq %r12
+; CHECK-NEXT: .cfi_def_cfa_offset 48
+; CHECK-NEXT: pushq %rbx
+; CHECK-NEXT: .cfi_def_cfa_offset 56
+; CHECK-NEXT: pushq %rax
+; CHECK-NEXT: .cfi_def_cfa_offset 64
+; CHECK-NEXT: .cfi_offset %rbx, -56
+; CHECK-NEXT: .cfi_offset %r12, -48
+; CHECK-NEXT: .cfi_offset %r13, -40
+; CHECK-NEXT: .cfi_offset %r14, -32
+; CHECK-NEXT: .cfi_offset %r15, -24
+; CHECK-NEXT: .cfi_offset %rbp, -16
+; CHECK-NEXT: movq %rdi, (%rsp) # 8-byte Spill
+; CHECK-NEXT: movabsq $nocsr, %rax
+; CHECK-NEXT: callq *%rax
+; CHECK-NEXT: movabsq $bar, %rax
+; CHECK-NEXT: movq (%rsp), %rbx # 8-byte Reload
+; CHECK-NEXT: movq %rbx, %rdi
+; CHECK-NEXT: callq *%rax
+; CHECK-NEXT: .Ltmp0:
+; CHECK-NEXT: movq %rbx, (%rsp) # 8-byte Spill
+; CHECK-NEXT: movabsq $nocsr, %rax
+; CHECK-NEXT: callq *%rax
+; CHECK-NEXT: movq (%rsp), %rax # 8-byte Reload
+; CHECK-NEXT: addq $8, %rsp
+; CHECK-NEXT: .cfi_def_cfa_offset 56
+; CHECK-NEXT: popq %rbx
+; CHECK-NEXT: .cfi_def_cfa_offset 48
+; CHECK-NEXT: popq %r12
+; CHECK-NEXT: .cfi_def_cfa_offset 40
+; CHECK-NEXT: popq %r13
+; CHECK-NEXT: .cfi_def_cfa_offset 32
+; CHECK-NEXT: popq %r14
+; CHECK-NEXT: .cfi_def_cfa_offset 24
+; CHECK-NEXT: popq %r15
+; CHECK-NEXT: .cfi_def_cfa_offset 16
+; CHECK-NEXT: popq %rbp
+; CHECK-NEXT: .cfi_def_cfa_offset 8
+; CHECK-NEXT: retq
+entry:
+ ; force spill %arg on stack.
+ call void @nocsr()
+ br label %do_call
+
+do_call:
+ ; Basic block with two use intructions inside:
+ ; copy to rdi as an argument to call and use in statepoint instruction as gc-live and deopt value.
+ %statepoint_token = call token (i64, i32, ptr, i32, i32, ...) @llvm.experimental.gc.statepoint.p0(i64 2882400000, i32 0, ptr elementtype(void (ptr addrspace(1))) @bar, i32 1, i32 0, ptr addrspace(1) %arg, i32 0, i32 0) [ "deopt"(ptr addrspace(1) %arg), "gc-live"(ptr addrspace(1) %arg) ]
+ %arg.reloc = call coldcc ptr addrspace(1) @llvm.experimental.gc.relocate.p1(token %statepoint_token, i32 0, i32 0)
+ br label %next
+
+next:
+ ; force spill %arg.reloc on stack.
+ call void @nocsr()
+ ret ptr addrspace(1) %arg.reloc
+}
+
+declare void @nocsr() "no_callee_saved_registers"
+declare void @bar(ptr addrspace(1))
+declare token @llvm.experimental.gc.statepoint.p0(i64 immarg, i32 immarg, ptr, i32 immarg, i32 immarg, ...)
+declare ptr addrspace(1) @llvm.experimental.gc.relocate.p1(token, i32 immarg, i32 immarg)
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