51387a8c28
The stack slot reuse code had a really amusing bug. We ended up only reusing a stack slot exact once (initial use + reuse) within a basic block. If we had a third statepoint to process, we ended up allocating a new set of stack slots. If we crossed a basic block boundary, the set got cleared. As a result, code which is invoke heavy doesn't see the problem, but multiple calls within a basic block does. Net result: as we optimize invokes into calls, lowering gets worse. The root error here is that the bitmap uses by the custom allocator wasn't kept in sync. The result was that we ended up resizing the bitmap on the next statepoint (to handle the cross block case), reset the bit once, but then never reset it again. Differential Revision: https://reviews.llvm.org/D25243 llvm-svn: 289509
137 lines
8.2 KiB
LLVM
137 lines
8.2 KiB
LLVM
; RUN: llc -stack-symbol-ordering=0 < %s | FileCheck %s
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target datalayout = "e-i64:64-f80:128-n8:16:32:64-S128"
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target triple = "x86_64-pc-linux-gnu"
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; This test is checking to make sure that we reuse the same stack slots
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; for GC values spilled over two different call sites. Since the order
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; of GC arguments differ, niave lowering code would insert loads and
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; stores to rearrange items on the stack. We need to make sure (for
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; performance) that this doesn't happen.
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define i32 @back_to_back_calls(i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c) #1 gc "statepoint-example" {
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; CHECK-LABEL: back_to_back_calls
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; The exact stores don't matter, but there need to be three stack slots created
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; CHECK: movq %rdi, 16(%rsp)
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; CHECK: movq %rdx, 8(%rsp)
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; CHECK: movq %rsi, (%rsp)
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; There should be no more than three moves
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; CHECK-NOT: movq
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%safepoint_token = tail call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0, i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c)
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%a1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 12)
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%b1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 13)
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%c1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 14)
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; CHECK: callq
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; This is the key check. There should NOT be any memory moves here
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; CHECK-NOT: movq
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%safepoint_token2 = tail call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0, i32 addrspace(1)* %c1, i32 addrspace(1)* %b1, i32 addrspace(1)* %a1)
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%a2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token2, i32 12, i32 14)
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%b2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token2, i32 12, i32 13)
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%c2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token2, i32 12, i32 12)
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; CHECK: callq
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ret i32 1
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}
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; This test simply checks that minor changes in vm state don't prevent slots
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; being reused for gc values.
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define i32 @reserve_first(i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c) #1 gc "statepoint-example" {
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; CHECK-LABEL: reserve_first
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; The exact stores don't matter, but there need to be three stack slots created
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; CHECK: movq %rdi, 16(%rsp)
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; CHECK: movq %rdx, 8(%rsp)
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; CHECK: movq %rsi, (%rsp)
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%safepoint_token = tail call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0, i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c)
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%a1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 12)
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%b1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 13)
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%c1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 14)
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; CHECK: callq
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; This is the key check. There should NOT be any memory moves here
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; CHECK-NOT: movq
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%safepoint_token2 = tail call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 addrspace(1)* %a1, i32 0, i32 addrspace(1)* %c1, i32 0, i32 0, i32 addrspace(1)* %c1, i32 addrspace(1)* %b1, i32 addrspace(1)* %a1)
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%a2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token2, i32 12, i32 14)
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%b2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token2, i32 12, i32 13)
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%c2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token2, i32 12, i32 12)
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; CHECK: callq
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ret i32 1
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}
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; Check that we reuse the same stack slot across multiple calls. The use of
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; more than two calls here is critical. We've had a bug which allowed reuse
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; exactly once which went undetected for a long time.
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define i32 @back_to_back_deopt(i32 %a, i32 %b, i32 %c) #1
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gc "statepoint-example" {
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; CHECK-LABEL: back_to_back_deopt
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; The exact stores don't matter, but there need to be three stack slots created
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; CHECK: movl %ebx, 12(%rsp)
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; CHECK: movl %ebp, 8(%rsp)
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; CHECK: movl %r14d, 4(%rsp)
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; CHECK: callq
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; CHECK: movl %ebx, 12(%rsp)
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; CHECK: movl %ebp, 8(%rsp)
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; CHECK: movl %r14d, 4(%rsp)
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; CHECK: callq
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; CHECK: movl %ebx, 12(%rsp)
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; CHECK: movl %ebp, 8(%rsp)
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; CHECK: movl %r14d, 4(%rsp)
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; CHECK: callq
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; CHECK: movl %ebx, 12(%rsp)
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; CHECK: movl %ebp, 8(%rsp)
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; CHECK: movl %r14d, 4(%rsp)
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; CHECK: callq
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call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 3, i32 %a, i32 %b, i32 %c)
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call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 3, i32 %a, i32 %b, i32 %c)
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call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 3, i32 %a, i32 %b, i32 %c)
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call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 3, i32 %a, i32 %b, i32 %c)
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ret i32 1
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}
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; Test that stack slots are reused for invokes
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define i32 @back_to_back_invokes(i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c) #1 gc "statepoint-example" personality i32 ()* @"personality_function" {
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; CHECK-LABEL: back_to_back_invokes
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entry:
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; The exact stores don't matter, but there need to be three stack slots created
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; CHECK: movq %rdi, 16(%rsp)
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; CHECK: movq %rdx, 8(%rsp)
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; CHECK: movq %rsi, (%rsp)
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; CHECK: callq
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%safepoint_token = invoke token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0, i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c)
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to label %normal_return unwind label %exceptional_return
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normal_return:
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%a1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 12)
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%b1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 13)
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%c1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 14)
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; Should work even through bitcasts
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%c1.casted = bitcast i32 addrspace(1)* %c1 to i8 addrspace(1)*
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; This is the key check. There should NOT be any memory moves here
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; CHECK-NOT: movq
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; CHECK: callq
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%safepoint_token2 = invoke token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0, i8 addrspace(1)* %c1.casted, i32 addrspace(1)* %b1, i32 addrspace(1)* %a1)
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to label %normal_return2 unwind label %exceptional_return2
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normal_return2:
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%a2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token2, i32 12, i32 14)
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%b2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token2, i32 12, i32 13)
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%c2 = tail call coldcc i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token %safepoint_token2, i32 12, i32 12)
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ret i32 1
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exceptional_return:
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%landing_pad = landingpad { i8*, i32 }
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cleanup
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ret i32 0
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exceptional_return2:
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%landing_pad2 = landingpad { i8*, i32 }
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cleanup
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ret i32 0
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}
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; Function Attrs: nounwind
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declare i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token, i32, i32) #3
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declare i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token, i32, i32) #3
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declare token @llvm.experimental.gc.statepoint.p0f_isVoidf(i64, i32, void ()*, i32, i32, ...)
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declare i32 @"personality_function"()
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attributes #1 = { uwtable }
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