691 lines
19 KiB
LLVM
691 lines
19 KiB
LLVM
; RUN: opt < %s -S -analyze -scalar-evolution | FileCheck %s
|
|
|
|
; Positive and negative tests for inferring flags like nsw from
|
|
; reasoning about how a poison value from overflow would trigger
|
|
; undefined behavior.
|
|
|
|
define void @foo() {
|
|
ret void
|
|
}
|
|
|
|
; Example where an add should get the nsw flag, so that a sext can be
|
|
; distributed over the add.
|
|
define void @test-add-nsw(float* %input, i32 %offset, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-add-nsw
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {%offset,+,1}<nsw>
|
|
%index32 = add nsw i32 %i, %offset
|
|
|
|
; CHECK: %index64 =
|
|
; CHECK: --> {(sext i32 %offset to i64),+,1}<nsw>
|
|
%index64 = sext i32 %index32 to i64
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i64 %index64
|
|
%nexti = add nsw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
call void @foo()
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Example where an add should get the nuw flag.
|
|
define void @test-add-nuw(float* %input, i32 %offset, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-add-nuw
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {%offset,+,1}<nuw>
|
|
%index32 = add nuw i32 %i, %offset
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %index32
|
|
%nexti = add nuw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
define void @test-add-nuw-from-icmp(float* %input, i32 %offset,
|
|
i32 %numIterations) {
|
|
; CHECK-LABEL: @test-add-nuw-from-icmp
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {%offset,+,1}<nuw>
|
|
%index32 = add nuw i32 %i, %offset
|
|
%cmp = icmp sgt i32 %index32, 0
|
|
%cmp.idx = sext i1 %cmp to i32
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %cmp.idx
|
|
%nexti = add nuw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; With no load to trigger UB from poison, we cannot infer nsw.
|
|
define void @test-add-no-load(float* %input, i32 %offset, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-add-no-load
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {%offset,+,1}<nw>
|
|
%index32 = add nsw i32 %i, %offset
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %index32
|
|
%nexti = add nuw i32 %i, 1
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; The current code is only supposed to look at the loop header, so
|
|
; it should not infer nsw in this case, as that would require looking
|
|
; outside the loop header.
|
|
define void @test-add-not-header(float* %input, i32 %offset, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-add-not-header
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop2 ], [ 0, %entry ]
|
|
br label %loop2
|
|
loop2:
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {%offset,+,1}<nw>
|
|
%index32 = add nsw i32 %i, %offset
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %index32
|
|
%nexti = add nsw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Same thing as test-add-not-header, but in this case only the load
|
|
; instruction is outside the loop header.
|
|
define void @test-add-not-header2(float* %input, i32 %offset, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-add-not-header2
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop2 ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {%offset,+,1}<nsw>
|
|
%index32 = add nsw i32 %i, %offset
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %index32
|
|
%nexti = add nsw i32 %i, 1
|
|
br label %loop2
|
|
loop2:
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Similar to test-add-not-header, but in this case the load
|
|
; instruction may not be executed.
|
|
define void @test-add-not-header3(float* %input, i32 %offset, i32 %numIterations,
|
|
i1* %cond_buf) {
|
|
; CHECK-LABEL: @test-add-not-header3
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop2 ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {%offset,+,1}<nw>
|
|
%index32 = add nsw i32 %i, %offset
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %index32
|
|
%nexti = add nsw i32 %i, 1
|
|
%cond = load volatile i1, i1* %cond_buf
|
|
br i1 %cond, label %loop2, label %exit
|
|
loop2:
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Same thing as test-add-not-header2, except we have a few extra
|
|
; blocks.
|
|
define void @test-add-not-header4(float* %input, i32 %offset, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-add-not-header4
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop2 ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {%offset,+,1}<nsw>
|
|
%index32 = add nsw i32 %i, %offset
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %index32
|
|
%nexti = add nsw i32 %i, 1
|
|
br label %loop3
|
|
loop3:
|
|
br label %loop4
|
|
loop4:
|
|
br label %loop2
|
|
loop2:
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Demonstrate why we need a Visited set in llvm::isKnownNotFullPoison.
|
|
define void @test-add-not-header5(float* %input, i32 %offset) {
|
|
; CHECK-LABEL: @test-add-not-header5
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {%offset,+,1}<nw>
|
|
%index32 = add nsw i32 %i, %offset
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %index32
|
|
%nexti = add nsw i32 %i, 1
|
|
br label %loop
|
|
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; The call instruction makes it not guaranteed that the add will be
|
|
; executed, since it could run forever or throw an exception, so we
|
|
; cannot assume that the UB is realized.
|
|
define void @test-add-call(float* %input, i32 %offset, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-add-call
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {%offset,+,1}<nw>
|
|
call void @foo()
|
|
%index32 = add nsw i32 %i, %offset
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %index32
|
|
%nexti = add nsw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Same issue as test-add-call, but this time the call is between the
|
|
; producer of poison and the load that consumes it.
|
|
define void @test-add-call2(float* %input, i32 %offset, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-add-call2
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {%offset,+,1}<nw>
|
|
%index32 = add nsw i32 %i, %offset
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %index32
|
|
%nexti = add nsw i32 %i, 1
|
|
call void @foo()
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Without inbounds, GEP does not propagate poison in the very
|
|
; conservative approach used here.
|
|
define void @test-add-no-inbounds(float* %input, i32 %offset, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-add-no-inbounds
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {%offset,+,1}<nw>
|
|
%index32 = add nsw i32 %i, %offset
|
|
|
|
%ptr = getelementptr float, float* %input, i32 %index32
|
|
%nexti = add nsw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Multiplication by a non-zero constant propagates poison if there is
|
|
; a nuw or nsw flag on the multiplication.
|
|
define void @test-add-mul-propagates(float* %input, i32 %offset, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-add-mul-propagates
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {%offset,+,1}<nsw>
|
|
%index32 = add nsw i32 %i, %offset
|
|
|
|
%indexmul = mul nuw i32 %index32, 2
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %indexmul
|
|
%nexti = add nsw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Multiplication by a non-constant should not propagate poison in the
|
|
; very conservative approach used here.
|
|
define void @test-add-mul-no-propagation(float* %input, i32 %offset, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-add-mul-no-propagation
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {%offset,+,1}<nw>
|
|
%index32 = add nsw i32 %i, %offset
|
|
|
|
%indexmul = mul nsw i32 %index32, %offset
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %indexmul
|
|
%nexti = add nsw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Multiplication by a non-zero constant does not propagate poison
|
|
; without a no-wrap flag.
|
|
define void @test-add-mul-no-propagation2(float* %input, i32 %offset, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-add-mul-no-propagation2
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {%offset,+,1}<nw>
|
|
%index32 = add nsw i32 %i, %offset
|
|
|
|
%indexmul = mul i32 %index32, 2
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %indexmul
|
|
%nexti = add nsw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Division by poison triggers UB.
|
|
define void @test-add-div(float* %input, i32 %offset, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-add-div
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %j =
|
|
; CHECK: --> {%offset,+,1}<nsw>
|
|
%j = add nsw i32 %i, %offset
|
|
|
|
%q = sdiv i32 %numIterations, %j
|
|
%nexti = add nsw i32 %i, 1
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Remainder of poison by non-poison divisor does not trigger UB.
|
|
define void @test-add-div2(float* %input, i32 %offset, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-add-div2
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %j =
|
|
; CHECK: --> {%offset,+,1}<nw>
|
|
%j = add nsw i32 %i, %offset
|
|
|
|
%q = sdiv i32 %j, %numIterations
|
|
%nexti = add nsw i32 %i, 1
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Store to poison address triggers UB.
|
|
define void @test-add-store(float* %input, i32 %offset, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-add-store
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {%offset,+,1}<nsw>
|
|
%index32 = add nsw i32 %i, %offset
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %index32
|
|
%nexti = add nsw i32 %i, 1
|
|
store float 1.0, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Three sequential adds where the middle add should have nsw. There is
|
|
; a special case for sequential adds and this test covers that. We have to
|
|
; put the final add first in the program since otherwise the special case
|
|
; is not triggered, hence the strange basic block ordering.
|
|
define void @test-add-twice(float* %input, i32 %offset, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-add-twice
|
|
entry:
|
|
br label %loop
|
|
loop2:
|
|
; CHECK: %seq =
|
|
; CHECK: --> {(2 + %offset),+,1}<nw>
|
|
%seq = add nsw nuw i32 %index32, 1
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop2 ], [ 0, %entry ]
|
|
|
|
%j = add nsw i32 %i, 1
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {(1 + %offset)<nsw>,+,1}<nsw>
|
|
%index32 = add nsw i32 %j, %offset
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %index32
|
|
%nexti = add nsw i32 %i, 1
|
|
store float 1.0, float* %ptr, align 4
|
|
br label %loop2
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Example where a mul should get the nsw flag, so that a sext can be
|
|
; distributed over the mul.
|
|
define void @test-mul-nsw(float* %input, i32 %stride, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-mul-nsw
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {0,+,%stride}<nsw>
|
|
%index32 = mul nsw i32 %i, %stride
|
|
|
|
; CHECK: %index64 =
|
|
; CHECK: --> {0,+,(sext i32 %stride to i64)}<nsw>
|
|
%index64 = sext i32 %index32 to i64
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i64 %index64
|
|
%nexti = add nsw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Example where a mul should get the nuw flag.
|
|
define void @test-mul-nuw(float* %input, i32 %stride, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-mul-nuw
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {0,+,%stride}<nuw>
|
|
%index32 = mul nuw i32 %i, %stride
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %index32
|
|
%nexti = add nuw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Example where a shl should get the nsw flag, so that a sext can be
|
|
; distributed over the shl.
|
|
define void @test-shl-nsw(float* %input, i32 %start, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-shl-nsw
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ %start, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {(256 * %start),+,256}<nsw>
|
|
%index32 = shl nsw i32 %i, 8
|
|
|
|
; CHECK: %index64 =
|
|
; CHECK: --> {(sext i32 (256 * %start) to i64),+,256}<nsw>
|
|
%index64 = sext i32 %index32 to i64
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i64 %index64
|
|
%nexti = add nsw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Example where a shl should get the nuw flag.
|
|
define void @test-shl-nuw(float* %input, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-shl-nuw
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {0,+,512}<nuw>
|
|
%index32 = shl nuw i32 %i, 9
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %index32
|
|
%nexti = add nuw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Example where a sub should *not* get the nsw flag, because of how
|
|
; scalar evolution represents A - B as A + (-B) and -B can wrap even
|
|
; in cases where A - B does not.
|
|
define void @test-sub-no-nsw(float* %input, i32 %start, i32 %sub, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-sub-no-nsw
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ %start, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {((-1 * %sub) + %start),+,1}<nw>
|
|
%index32 = sub nsw i32 %i, %sub
|
|
%index64 = sext i32 %index32 to i64
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i64 %index64
|
|
%nexti = add nsw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Example where a sub should get the nsw flag as the RHS cannot be the
|
|
; minimal signed value.
|
|
define void @test-sub-nsw(float* %input, i32 %start, i32 %sub, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-sub-nsw
|
|
entry:
|
|
%halfsub = ashr i32 %sub, 1
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ %start, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {((-1 * %halfsub)<nsw> + %start)<nsw>,+,1}<nsw>
|
|
%index32 = sub nsw i32 %i, %halfsub
|
|
%index64 = sext i32 %index32 to i64
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i64 %index64
|
|
%nexti = add nsw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Example where a sub should get the nsw flag, since the LHS is non-negative,
|
|
; which implies that the RHS cannot be the minimal signed value.
|
|
define void @test-sub-nsw-lhs-non-negative(float* %input, i32 %sub, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-sub-nsw-lhs-non-negative
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {(-1 * %sub),+,1}<nsw>
|
|
%index32 = sub nsw i32 %i, %sub
|
|
|
|
; CHECK: %index64 =
|
|
; CHECK: --> {(sext i32 (-1 * %sub) to i64),+,1}<nsw>
|
|
%index64 = sext i32 %index32 to i64
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i64 %index64
|
|
%nexti = add nsw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Two adds with a sub in the middle and the sub should have nsw. There is
|
|
; a special case for sequential adds/subs and this test covers that. We have to
|
|
; put the final add first in the program since otherwise the special case
|
|
; is not triggered, hence the strange basic block ordering.
|
|
define void @test-sub-with-add(float* %input, i32 %offset, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-sub-with-add
|
|
entry:
|
|
br label %loop
|
|
loop2:
|
|
; CHECK: %seq =
|
|
; CHECK: --> {(2 + (-1 * %offset)),+,1}<nw>
|
|
%seq = add nsw nuw i32 %index32, 1
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop2 ], [ 0, %entry ]
|
|
|
|
%j = add nsw i32 %i, 1
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {(1 + (-1 * %offset))<nsw>,+,1}<nsw>
|
|
%index32 = sub nsw i32 %j, %offset
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %index32
|
|
%nexti = add nsw i32 %i, 1
|
|
store float 1.0, float* %ptr, align 4
|
|
br label %loop2
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
|
|
; Subtraction of two recurrences. The addition in the SCEV that this
|
|
; maps to is NSW, but the negation of the RHS does not since that
|
|
; recurrence could be the most negative representable value.
|
|
define void @subrecurrences(i32 %outer_l, i32 %inner_l, i32 %val) {
|
|
; CHECK-LABEL: @subrecurrences
|
|
entry:
|
|
br label %outer
|
|
|
|
outer:
|
|
%o_idx = phi i32 [ 0, %entry ], [ %o_idx.inc, %outer.be ]
|
|
%o_idx.inc = add nsw i32 %o_idx, 1
|
|
%cond = icmp eq i32 %o_idx, %val
|
|
br i1 %cond, label %inner, label %outer.be
|
|
|
|
inner:
|
|
%i_idx = phi i32 [ 0, %outer ], [ %i_idx.inc, %inner ]
|
|
%i_idx.inc = add nsw i32 %i_idx, 1
|
|
; CHECK: %v =
|
|
; CHECK-NEXT: --> {{[{][{]}}-1,+,-1}<nw><%outer>,+,1}<nsw><%inner>
|
|
%v = sub nsw i32 %i_idx, %o_idx.inc
|
|
%forub = udiv i32 1, %v
|
|
%cond2 = icmp eq i32 %i_idx, %inner_l
|
|
br i1 %cond2, label %outer.be, label %inner
|
|
|
|
outer.be:
|
|
%cond3 = icmp eq i32 %o_idx, %outer_l
|
|
br i1 %cond3, label %exit, label %outer
|
|
|
|
exit:
|
|
ret void
|
|
}
|