llvm-6502/test/Transforms/JumpThreading/select.ll
Dinesh Dwivedi 199da600f3 Fixed jump threading going to infinite loop.
This patch add code to remove unreachable blocks from function
as they may cause jump threading to stuck in infinite loop.

Differential Revision: http://reviews.llvm.org/D3991



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211103 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-17 14:34:19 +00:00

223 lines
5.4 KiB
LLVM

; RUN: opt -S -jump-threading < %s | FileCheck %s
declare void @foo()
declare void @bar()
declare void @baz()
declare void @quux()
; Jump threading of branch with select as condition.
; Mostly theoretical since instruction combining simplifies all selects of
; booleans where at least one operand is true/false/undef.
; CHECK-LABEL: @test_br(
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond, label %L1,
define void @test_br(i1 %cond, i1 %value) nounwind {
entry:
br i1 %cond, label %L0, label %L3
L0:
%expr = select i1 %cond, i1 true, i1 %value
br i1 %expr, label %L1, label %L2
L1:
call void @foo()
ret void
L2:
call void @bar()
ret void
L3:
call void @baz()
br label %L0
}
; Jump threading of switch with select as condition.
; CHECK-LABEL: @test_switch(
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond, label %L1,
define void @test_switch(i1 %cond, i8 %value) nounwind {
entry:
br i1 %cond, label %L0, label %L4
L0:
%expr = select i1 %cond, i8 1, i8 %value
switch i8 %expr, label %L3 [i8 1, label %L1 i8 2, label %L2]
L1:
call void @foo()
ret void
L2:
call void @bar()
ret void
L3:
call void @baz()
ret void
L4:
call void @quux()
br label %L0
}
; Make sure the blocks in the indirectbr test aren't trivially removable as
; successors by taking their addresses.
@anchor = constant [3 x i8*] [
i8* blockaddress(@test_indirectbr, %L1),
i8* blockaddress(@test_indirectbr, %L2),
i8* blockaddress(@test_indirectbr, %L3)
]
; Jump threading of indirectbr with select as address.
; CHECK-LABEL: @test_indirectbr(
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond, label %L1, label %L3
define void @test_indirectbr(i1 %cond, i8* %address) nounwind {
entry:
br i1 %cond, label %L0, label %L3
L0:
%indirect.goto.dest = select i1 %cond, i8* blockaddress(@test_indirectbr, %L1), i8* %address
indirectbr i8* %indirect.goto.dest, [label %L1, label %L2, label %L3]
L1:
call void @foo()
ret void
L2:
call void @bar()
ret void
L3:
call void @baz()
ret void
}
; A more complicated case: the condition is a select based on a comparison.
; CHECK-LABEL: @test_switch_cmp(
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond, label %L0, label %[[THREADED:[A-Za-z.0-9]+]]
; CHECK: [[THREADED]]:
; CHECK-NEXT: call void @quux
; CHECK-NEXT: br label %L1
define void @test_switch_cmp(i1 %cond, i32 %val, i8 %value) nounwind {
entry:
br i1 %cond, label %L0, label %L4
L0:
%val.phi = phi i32 [%val, %entry], [-1, %L4]
%cmp = icmp slt i32 %val.phi, 0
%expr = select i1 %cmp, i8 1, i8 %value
switch i8 %expr, label %L3 [i8 1, label %L1 i8 2, label %L2]
L1:
call void @foo()
ret void
L2:
call void @bar()
ret void
L3:
call void @baz()
ret void
L4:
call void @quux()
br label %L0
}
; Make sure the edge value of %0 from entry to L2 includes 0 and L3 is
; reachable.
; CHECK: test_switch_default
; CHECK: entry:
; CHECK: load
; CHECK: icmp
; CHECK: [[THREADED:[A-Za-z.0-9]+]]:
; CHECK: store
; CHECK: br
; CHECK: L2:
; CHECK: icmp
define void @test_switch_default(i32* nocapture %status) nounwind {
entry:
%0 = load i32* %status, align 4
switch i32 %0, label %L2 [
i32 5061, label %L1
i32 0, label %L2
]
L1:
store i32 10025, i32* %status, align 4
br label %L2
L2:
%1 = load i32* %status, align 4
%cmp57.i = icmp eq i32 %1, 0
br i1 %cmp57.i, label %L3, label %L4
L3:
store i32 10000, i32* %status, align 4
br label %L4
L4:
ret void
}
define void @unfold1(double %x, double %y) nounwind {
entry:
%sub = fsub double %x, %y
%cmp = fcmp ogt double %sub, 1.000000e+01
br i1 %cmp, label %cond.end4, label %cond.false
cond.false: ; preds = %entry
%add = fadd double %x, %y
%cmp1 = fcmp ogt double %add, 1.000000e+01
%add. = select i1 %cmp1, double %add, double 0.000000e+00
br label %cond.end4
cond.end4: ; preds = %entry, %cond.false
%cond5 = phi double [ %add., %cond.false ], [ %sub, %entry ]
%cmp6 = fcmp oeq double %cond5, 0.000000e+00
br i1 %cmp6, label %if.then, label %if.end
if.then: ; preds = %cond.end4
call void @foo()
br label %if.end
if.end: ; preds = %if.then, %cond.end4
ret void
; CHECK-LABEL: @unfold1
; CHECK: br i1 %cmp, label %cond.end4, label %cond.false
; CHECK: br i1 %cmp1, label %cond.end4, label %if.then
; CHECK: br i1 %cmp6, label %if.then, label %if.end
; CHECK: br label %if.end
}
define void @unfold2(i32 %x, i32 %y) nounwind {
entry:
%sub = sub nsw i32 %x, %y
%cmp = icmp sgt i32 %sub, 10
br i1 %cmp, label %cond.end4, label %cond.false
cond.false: ; preds = %entry
%add = add nsw i32 %x, %y
%cmp1 = icmp sgt i32 %add, 10
%add. = select i1 %cmp1, i32 0, i32 %add
br label %cond.end4
cond.end4: ; preds = %entry, %cond.false
%cond5 = phi i32 [ %add., %cond.false ], [ %sub, %entry ]
%cmp6 = icmp eq i32 %cond5, 0
br i1 %cmp6, label %if.then, label %if.end
if.then: ; preds = %cond.end4
call void @foo()
br label %if.end
if.end: ; preds = %if.then, %cond.end4
ret void
; CHECK-LABEL: @unfold2
; CHECK: br i1 %cmp, label %if.end, label %cond.false
; CHECK: br i1 %cmp1, label %if.then, label %cond.end4
; CHECK: br i1 %cmp6, label %if.then, label %if.end
; CHECK: br label %if.end
}