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[ISEL][BitTestBlock] pre-commit test for D109103
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Upload a test that shows ISEL taking a SwitchInst that has an
unreachable BB for a default target being lowered to an unconditional
jump off the end of a function.

Link: https://bugs.llvm.org/show_bug.cgi?id=50080
Link: ClangBuiltLinux/linux#679
Link: ClangBuiltLinux/linux#1440

Reviewed By: craig.topper, hans

Differential Revision: https://reviews.llvm.org/D109106
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nickdesaulniers authored and memfrob committed Oct 4, 2022
1 parent c26084f commit 4cd8336
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46 changes: 46 additions & 0 deletions llvm/test/CodeGen/X86/SwitchLowering.ll
Original file line number Diff line number Diff line change
Expand Up @@ -62,3 +62,49 @@ bb7: ; preds = %bb, %bb

declare void @foo(i8)

define i32 @baz(i32 %0) {
; FIXME: Get rid of this conditional jump and bit test in .LBB1_1.
; FIXME: .LBB1_4 should not have .LBB1_1 as a predecessor, or be past the end
; FIXME: of the function.
; CHECK-LABEL: baz:
; CHECK: # %bb.0:
; CHECK-NEXT: xorl %eax, %eax
; CHECK-NEXT: movl {{[0-9]+}}(%esp), %ecx
; CHECK-NEXT: movl $13056, %edx # imm = 0x3300
; CHECK-NEXT: btl %ecx, %edx
; CHECK-NEXT: jae .LBB1_1
; CHECK-NEXT: # %bb.3: # %return
; CHECK-NEXT: retl
; CHECK-NEXT: .LBB1_1:
; CHECK-NEXT: movl $48, %eax
; CHECK-NEXT: btl %ecx, %eax
; CHECK-NEXT: jae .LBB1_4
; CHECK-NEXT: # %bb.2: # %sw.epilog8
; CHECK-NEXT: movl $1, %eax
; CHECK-NEXT: retl
; CHECK-NEXT: .LBB1_4: # %if.then.unreachabledefault
switch i32 %0, label %if.then.unreachabledefault [
i32 4, label %sw.epilog8
i32 5, label %sw.epilog8
i32 8, label %sw.bb2
i32 9, label %sw.bb2
i32 12, label %sw.bb4
i32 13, label %sw.bb4
]

sw.bb2:
br label %return

sw.bb4:
br label %return

sw.epilog8:
br label %return

if.then.unreachabledefault:
unreachable

return:
%retval.0 = phi i32 [ 1, %sw.epilog8 ], [ 0, %sw.bb2 ], [ 0, %sw.bb4 ]
ret i32 %retval.0
}
117 changes: 117 additions & 0 deletions llvm/test/CodeGen/X86/switch-bit-test-unreachable-default.ll
Original file line number Diff line number Diff line change
@@ -0,0 +1,117 @@
; RUN: llc -mtriple=x86_64-- -global-isel=0 -print-after=finalize-isel \
; RUN: -stop-after=finalize-isel %s -o /dev/null 2>&1 | \
; RUN: FileCheck %s --check-prefix=CHECK-SDISEL
; RUN: llc -mtriple=x86_64-- -global-isel=1 -print-after=finalize-isel \
; RUN: -stop-after=finalize-isel %s -o /dev/null 2>&1 | \
; RUN: FileCheck %s --check-prefix=CHECK-GISEL

; PR50080
define i32 @baz(i32 %0) {
; FIXME: Get rid of this conditional jump and bit test in bb.5.
; FIXME: bb.2 should not have bb.5 as a predecessor.
; CHECK-SDISEL: bb.0 (%ir-block.1):
; CHECK-SDISEL: successors: %bb.4(0x80000000); %bb.4(100.00%)
; CHECK-SDISEL: liveins: $edi
; CHECK-SDISEL: %1:gr32 = COPY $edi
; CHECK-SDISEL: %2:gr32 = MOV32r0 implicit-def dead $eflags
; CHECK-SDISEL: %3:gr32 = COPY %1:gr32
; CHECK-SDISEL: bb.4 (%ir-block.1):
; CHECK-SDISEL: ; predecessors: %bb.0
; CHECK-SDISEL: successors: %bb.3(0x55555555), %bb.5(0x2aaaaaab); %bb.3(66.67%), %bb.5(33.33%)
; CHECK-SDISEL: %4:gr32 = MOV32ri 13056
; CHECK-SDISEL: BT32rr killed %4:gr32, %3:gr32, implicit-def $eflags
; CHECK-SDISEL: JCC_1 %bb.3, 2, implicit $eflags
; CHECK-SDISEL: bb.5 (%ir-block.1):
; CHECK-SDISEL: ; predecessors: %bb.4
; CHECK-SDISEL: successors: %bb.1(0x80000000), %bb.2(0x00000000); %bb.1(100.00%), %bb.2(0.00%)
; CHECK-SDISEL: %5:gr32 = MOV32ri 48
; CHECK-SDISEL: BT32rr killed %5:gr32, %3:gr32, implicit-def $eflags
; CHECK-SDISEL: JCC_1 %bb.1, 2, implicit $eflags
; CHECK-SDISEL: JMP_1 %bb.2
; CHECK-SDISEL: bb.1.sw.epilog8:
; CHECK-SDISEL: ; predecessors: %bb.5
; CHECK-SDISEL: successors: %bb.3(0x80000000); %bb.3(100.00%)
; CHECK-SDISEL: %6:gr32 = MOV32ri 1
; CHECK-SDISEL: JMP_1 %bb.3
; CHECK-SDISEL: bb.2.if.then.unreachabledefault:
; CHECK-SDISEL: ; predecessors: %bb.5
; CHECK-SDISEL: bb.3.return:
; CHECK-SDISEL: ; predecessors: %bb.4, %bb.1
; CHECK-SDISEL: %0:gr32 = PHI %2:gr32, %bb.4, %6:gr32, %bb.1
; CHECK-SDISEL: $eax = COPY %0:gr32
; CHECK-SDISEL: RET 0, $eax


; FIXME: Get rid of this conditional jump and bit test in bb.6.
; FIXME: bb.3 should not have bb.6 as a predecessor.
; CHECK-GISEL: bb.1 (%ir-block.1):
; CHECK-GISEL: successors: %bb.5(0x80000000); %bb.5(100.00%)
; CHECK-GISEL: liveins: $edi
; CHECK-GISEL: %0:gr32 = COPY $edi
; CHECK-GISEL: %16:gr32 = MOV32ri 1
; CHECK-GISEL: %17:gr32 = MOV32r0 implicit-def $eflags
; CHECK-GISEL: %2:gr32 = SUB32ri8 %0:gr32(tied-def 0), 0, implicit-def $eflags
; CHECK-GISEL: bb.5 (%ir-block.1):
; CHECK-GISEL: ; predecessors: %bb.1
; CHECK-GISEL: successors: %bb.4(0x55555555), %bb.6(0x2aaaaaab); %bb.4(66.67%), %bb.6(33.33%)
; CHECK-GISEL: %3:gr32 = MOV32ri 1
; CHECK-GISEL: %21:gr8 = COPY %2.sub_8bit:gr32
; CHECK-GISEL: $cl = COPY %21:gr8
; CHECK-GISEL: %4:gr32 = SHL32rCL %3:gr32(tied-def 0), implicit-def $eflags, implicit $cl
; CHECK-GISEL: %6:gr32 = AND32ri %4:gr32(tied-def 0), 13056, implicit-def $eflags
; CHECK-GISEL: %7:gr32 = MOV32r0 implicit-def $eflags
; CHECK-GISEL: CMP32rr %6:gr32, %7:gr32, implicit-def $eflags
; CHECK-GISEL: %20:gr8 = SETCCr 5, implicit $eflags
; CHECK-GISEL: TEST8ri %20:gr8, 1, implicit-def $eflags
; CHECK-GISEL: JCC_1 %bb.4, 5, implicit $eflags
; CHECK-GISEL: bb.6 (%ir-block.1):
; CHECK-GISEL: ; predecessors: %bb.5
; CHECK-GISEL: successors: %bb.2(0x80000000), %bb.3(0x00000000); %bb.2(100.00%), %bb.3(0.00%)
; CHECK-GISEL: %9:gr32 = MOV32ri 1
; CHECK-GISEL: %19:gr8 = COPY %2.sub_8bit:gr32
; CHECK-GISEL: $cl = COPY %19:gr8
; CHECK-GISEL: %10:gr32 = SHL32rCL %9:gr32(tied-def 0), implicit-def $eflags, implicit $cl
; CHECK-GISEL: %12:gr32 = AND32ri8 %10:gr32(tied-def 0), 48, implicit-def $eflags
; CHECK-GISEL: %13:gr32 = MOV32r0 implicit-def $eflags
; CHECK-GISEL: CMP32rr %12:gr32, %13:gr32, implicit-def $eflags
; CHECK-GISEL: %18:gr8 = SETCCr 5, implicit $eflags
; CHECK-GISEL: TEST8ri %18:gr8, 1, implicit-def $eflags
; CHECK-GISEL: JCC_1 %bb.2, 5, implicit $eflags
; CHECK-GISEL: JMP_1 %bb.3
; CHECK-GISEL: bb.2.sw.epilog8:
; CHECK-GISEL: ; predecessors: %bb.6
; CHECK-GISEL: successors: %bb.4(0x80000000); %bb.4(100.00%)
; CHECK-GISEL: JMP_1 %bb.4
; CHECK-GISEL: bb.3.if.then.unreachabledefault:
; CHECK-GISEL: ; predecessors: %bb.6
; CHECK-GISEL: bb.4.return:
; CHECK-GISEL: ; predecessors: %bb.5, %bb.2
; CHECK-GISEL: %15:gr32 = PHI %16:gr32, %bb.2, %17:gr32, %bb.5
; CHECK-GISEL: $eax = COPY %15:gr32
; CHECK-GISEL: RET 0, implicit $eax

switch i32 %0, label %if.then.unreachabledefault [
i32 4, label %sw.epilog8
i32 5, label %sw.epilog8
i32 8, label %sw.bb2
i32 9, label %sw.bb2
i32 12, label %sw.bb4
i32 13, label %sw.bb4
]

sw.bb2:
br label %return

sw.bb4:
br label %return

sw.epilog8:
br label %return

if.then.unreachabledefault:
unreachable

return:
%retval.0 = phi i32 [ 1, %sw.epilog8 ], [ 0, %sw.bb2 ], [ 0, %sw.bb4 ]
ret i32 %retval.0
}

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