3787ee4571
Relands commit 433c8d950c with fixes for
MIPS.
Similar to D102742, specifying the stack alignment via CodegenOpts means
that this flag gets dropped during LTO, unless the command line is
re-specified as a plugin opt. Instead, encode this information as a
module level attribute so that we don't have to expose this llvm
internal flag when linking the Linux kernel with LTO.
Looks like external dependencies might need a fix:
* https://github.com/llvm-hs/llvm-hs/issues/345
* https://github.com/halide/Halide/issues/6079
Link: https://github.com/ClangBuiltLinux/linux/issues/1377
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D103048
80 lines
2.3 KiB
LLVM
80 lines
2.3 KiB
LLVM
; This test is attempting to detect when we request forced re-alignment of the
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; stack to an alignment greater than would be available due to the ABI. We
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; arbitrarily force alignment up to 32-bytes for i386 hoping that this will
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; exceed any ABI provisions.
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;
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; RUN: llc < %s -mcpu=generic -stackrealign | FileCheck %s
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target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32-S128"
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target triple = "i386-unknown-linux-gnu"
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define i32 @f(i8* %p) nounwind {
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entry:
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%0 = load i8, i8* %p
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%conv = sext i8 %0 to i32
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ret i32 %conv
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}
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define i64 @g(i32 %i) nounwind {
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; CHECK-LABEL: g:
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; CHECK: pushl %ebp
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; CHECK-NEXT: movl %esp, %ebp
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; CHECK-NEXT: pushl
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; CHECK-NEXT: pushl
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; CHECK-NEXT: andl $-32, %esp
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; CHECK-NEXT: subl $32, %esp
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;
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; Now setup the base pointer (%esi).
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; CHECK-NEXT: movl %esp, %esi
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; CHECK-NOT: {{[^ ,]*}}, %esp
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;
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; The next adjustment of the stack is due to the alloca.
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; CHECK: movl %{{...}}, %esp
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; CHECK-NOT: {{[^ ,]*}}, %esp
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;
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; Next we set up the memset call.
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; CHECK: subl $20, %esp
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; CHECK-NOT: {{[^ ,]*}}, %esp
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; CHECK: pushl
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; CHECK: pushl
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; CHECK: pushl
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; CHECK: calll memset
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;
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; Deallocating 32 bytes of outgoing call frame for memset and
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; allocating 28 bytes for calling f yields a 4-byte adjustment:
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; CHECK-NEXT: addl $4, %esp
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; CHECK-NOT: {{[^ ,]*}}, %esp
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;
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; And move on to call 'f', and then restore the stack.
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; CHECK: pushl
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; CHECK-NOT: {{[^ ,]*}}, %esp
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; CHECK: calll f
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; CHECK-NEXT: addl $32, %esp
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; CHECK-NOT: {{[^ ,]*}}, %esp
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;
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; Restore %esp from %ebp (frame pointer) and subtract the size of
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; zone with callee-saved registers to pop them.
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; This is the state prior to stack realignment and the allocation of VLAs.
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; CHECK-NOT: popl
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; CHECK: leal -8(%ebp), %esp
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; CHECK-NEXT: popl
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; CHECK-NEXT: popl
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; CHECK-NEXT: popl %ebp
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; CHECK-NEXT: ret
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entry:
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br label %if.then
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if.then:
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%0 = alloca i8, i32 %i
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call void @llvm.memset.p0i8.i32(i8* %0, i8 0, i32 %i, i1 false)
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%call = call i32 @f(i8* %0)
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%conv = sext i32 %call to i64
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ret i64 %conv
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}
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declare void @llvm.memset.p0i8.i32(i8*, i8, i32, i1) nounwind
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!llvm.module.flags = !{!0}
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!0 = !{i32 2, !"override-stack-alignment", i32 32}
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