Sebastian Pop ad43499fc4 dependence analysis
Patch from Preston Briggs <preston.briggs@gmail.com>.

This is an updated version of the dependence-analysis patch, including an MIV
test based on Banerjee's inequalities.

It's a fairly complete implementation of the paper

    Practical Dependence Testing
    Gina Goff, Ken Kennedy, and Chau-Wen Tseng
    PLDI 1991

It cannot yet propagate constraints between coupled RDIV subscripts (discussed
in Section 5.3.2 of the paper).

It's organized as a FunctionPass with a single entry point that supports testing
for dependence between two instructions in a function. If there's no dependence,
it returns null. If there's a dependence, it returns a pointer to a Dependence
which can be queried about details (what kind of dependence, is it loop
independent, direction and distance vector entries, etc). I haven't included
every imaginable feature, but there's a good selection that should be adequate
for supporting many loop transformations. Of course, it can be extended as
necessary.

Included in the patch file are many test cases, commented with C code showing
the loops and array references.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165708 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-11 07:32:34 +00:00

510 lines
18 KiB
LLVM

; RUN: opt < %s -analyze -basicaa -da | FileCheck %s
; ModuleID = 'Coupled.bc'
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.6.0"
;; for (long int i = 0; i < 50; i++)
;; A[i][i] = ...
;; ... = A[i + 10][i + 9]
define void @couple0([100 x i32]* %A, i32* %B, i32 %n) nounwind uwtable ssp {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.02 = phi i64 [ 0, %entry ], [ %inc, %for.body ]
%B.addr.01 = phi i32* [ %B, %entry ], [ %incdec.ptr, %for.body ]
%conv = trunc i64 %i.02 to i32
%arrayidx1 = getelementptr inbounds [100 x i32]* %A, i64 %i.02, i64 %i.02
store i32 %conv, i32* %arrayidx1, align 4
%add = add nsw i64 %i.02, 9
%add2 = add nsw i64 %i.02, 10
%arrayidx4 = getelementptr inbounds [100 x i32]* %A, i64 %add2, i64 %add
%0 = load i32* %arrayidx4, align 4
; CHECK: da analyze - none!
%incdec.ptr = getelementptr inbounds i32* %B.addr.01, i64 1
store i32 %0, i32* %B.addr.01, align 4
%inc = add nsw i64 %i.02, 1
%cmp = icmp slt i64 %inc, 50
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
ret void
}
;; for (long int i = 0; i < 50; i++)
;; A[i][i] = ...
;; ... = A[i + 9][i + 9]
define void @couple1([100 x i32]* %A, i32* %B, i32 %n) nounwind uwtable ssp {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.02 = phi i64 [ 0, %entry ], [ %inc, %for.body ]
%B.addr.01 = phi i32* [ %B, %entry ], [ %incdec.ptr, %for.body ]
%conv = trunc i64 %i.02 to i32
%arrayidx1 = getelementptr inbounds [100 x i32]* %A, i64 %i.02, i64 %i.02
store i32 %conv, i32* %arrayidx1, align 4
%add = add nsw i64 %i.02, 9
%add2 = add nsw i64 %i.02, 9
%arrayidx4 = getelementptr inbounds [100 x i32]* %A, i64 %add2, i64 %add
%0 = load i32* %arrayidx4, align 4
; CHECK: da analyze - consistent flow [-9]!
%incdec.ptr = getelementptr inbounds i32* %B.addr.01, i64 1
store i32 %0, i32* %B.addr.01, align 4
%inc = add nsw i64 %i.02, 1
%cmp = icmp slt i64 %inc, 50
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
ret void
}
;; for (long int i = 0; i < 50; i++)
;; A[3*i - 6][3*i - 6] = ...
;; ... = A[i][i]
define void @couple2([100 x i32]* %A, i32* %B, i32 %n) nounwind uwtable ssp {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.02 = phi i64 [ 0, %entry ], [ %inc, %for.body ]
%B.addr.01 = phi i32* [ %B, %entry ], [ %incdec.ptr, %for.body ]
%conv = trunc i64 %i.02 to i32
%mul = mul nsw i64 %i.02, 3
%sub = add nsw i64 %mul, -6
%mul1 = mul nsw i64 %i.02, 3
%sub2 = add nsw i64 %mul1, -6
%arrayidx3 = getelementptr inbounds [100 x i32]* %A, i64 %sub2, i64 %sub
store i32 %conv, i32* %arrayidx3, align 4
%arrayidx5 = getelementptr inbounds [100 x i32]* %A, i64 %i.02, i64 %i.02
%0 = load i32* %arrayidx5, align 4
; CHECK: da analyze - flow [*|<]!
%incdec.ptr = getelementptr inbounds i32* %B.addr.01, i64 1
store i32 %0, i32* %B.addr.01, align 4
%inc = add nsw i64 %i.02, 1
%cmp = icmp slt i64 %inc, 50
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
ret void
}
;; for (long int i = 0; i < 50; i++)
;; A[3*i - 6][3*i - 5] = ...
;; ... = A[i][i]
define void @couple3([100 x i32]* %A, i32* %B, i32 %n) nounwind uwtable ssp {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.02 = phi i64 [ 0, %entry ], [ %inc, %for.body ]
%B.addr.01 = phi i32* [ %B, %entry ], [ %incdec.ptr, %for.body ]
%conv = trunc i64 %i.02 to i32
%mul = mul nsw i64 %i.02, 3
%sub = add nsw i64 %mul, -5
%mul1 = mul nsw i64 %i.02, 3
%sub2 = add nsw i64 %mul1, -6
%arrayidx3 = getelementptr inbounds [100 x i32]* %A, i64 %sub2, i64 %sub
store i32 %conv, i32* %arrayidx3, align 4
%arrayidx5 = getelementptr inbounds [100 x i32]* %A, i64 %i.02, i64 %i.02
%0 = load i32* %arrayidx5, align 4
; CHECK: da analyze - none!
%incdec.ptr = getelementptr inbounds i32* %B.addr.01, i64 1
store i32 %0, i32* %B.addr.01, align 4
%inc = add nsw i64 %i.02, 1
%cmp = icmp slt i64 %inc, 50
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
ret void
}
;; for (long int i = 0; i < 50; i++)
;; A[3*i - 6][3*i - n] = ...
;; ... = A[i][i]
define void @couple4([100 x i32]* %A, i32* %B, i32 %n) nounwind uwtable ssp {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.02 = phi i64 [ 0, %entry ], [ %inc, %for.body ]
%B.addr.01 = phi i32* [ %B, %entry ], [ %incdec.ptr, %for.body ]
%conv = trunc i64 %i.02 to i32
%mul = mul nsw i64 %i.02, 3
%conv1 = sext i32 %n to i64
%sub = sub nsw i64 %mul, %conv1
%mul2 = mul nsw i64 %i.02, 3
%sub3 = add nsw i64 %mul2, -6
%arrayidx4 = getelementptr inbounds [100 x i32]* %A, i64 %sub3, i64 %sub
store i32 %conv, i32* %arrayidx4, align 4
%arrayidx6 = getelementptr inbounds [100 x i32]* %A, i64 %i.02, i64 %i.02
%0 = load i32* %arrayidx6, align 4
; CHECK: da analyze - flow [*|<]!
%incdec.ptr = getelementptr inbounds i32* %B.addr.01, i64 1
store i32 %0, i32* %B.addr.01, align 4
%inc = add nsw i64 %i.02, 1
%cmp = icmp slt i64 %inc, 50
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
ret void
}
;; for (long int i = 0; i < 50; i++)
;; A[3*i - n + 1][3*i - n] = ...
;; ... = A[i][i]
define void @couple5([100 x i32]* %A, i32* %B, i32 %n) nounwind uwtable ssp {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.02 = phi i64 [ 0, %entry ], [ %inc, %for.body ]
%B.addr.01 = phi i32* [ %B, %entry ], [ %incdec.ptr, %for.body ]
%conv = trunc i64 %i.02 to i32
%mul = mul nsw i64 %i.02, 3
%conv1 = sext i32 %n to i64
%sub = sub nsw i64 %mul, %conv1
%mul2 = mul nsw i64 %i.02, 3
%conv3 = sext i32 %n to i64
%sub4 = sub nsw i64 %mul2, %conv3
%add = add nsw i64 %sub4, 1
%arrayidx5 = getelementptr inbounds [100 x i32]* %A, i64 %add, i64 %sub
store i32 %conv, i32* %arrayidx5, align 4
%arrayidx7 = getelementptr inbounds [100 x i32]* %A, i64 %i.02, i64 %i.02
%0 = load i32* %arrayidx7, align 4
; CHECK: da analyze - none!
%incdec.ptr = getelementptr inbounds i32* %B.addr.01, i64 1
store i32 %0, i32* %B.addr.01, align 4
%inc = add nsw i64 %i.02, 1
%cmp = icmp slt i64 %inc, 50
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
ret void
}
;; for (long int i = 0; i < 50; i++)
;; A[i][3*i - 6] = ...
;; ... = A[i][i]
define void @couple6([100 x i32]* %A, i32* %B, i32 %n) nounwind uwtable ssp {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.02 = phi i64 [ 0, %entry ], [ %inc, %for.body ]
%B.addr.01 = phi i32* [ %B, %entry ], [ %incdec.ptr, %for.body ]
%conv = trunc i64 %i.02 to i32
%mul = mul nsw i64 %i.02, 3
%sub = add nsw i64 %mul, -6
%arrayidx1 = getelementptr inbounds [100 x i32]* %A, i64 %i.02, i64 %sub
store i32 %conv, i32* %arrayidx1, align 4
%arrayidx3 = getelementptr inbounds [100 x i32]* %A, i64 %i.02, i64 %i.02
%0 = load i32* %arrayidx3, align 4
; CHECK: da analyze - flow [=|<]!
%incdec.ptr = getelementptr inbounds i32* %B.addr.01, i64 1
store i32 %0, i32* %B.addr.01, align 4
%inc = add nsw i64 %i.02, 1
%cmp = icmp slt i64 %inc, 50
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
ret void
}
;; for (long int i = 0; i < 50; i++)
;; A[i][3*i - 5] = ...
;; ... = A[i][i]
define void @couple7([100 x i32]* %A, i32* %B, i32 %n) nounwind uwtable ssp {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.02 = phi i64 [ 0, %entry ], [ %inc, %for.body ]
%B.addr.01 = phi i32* [ %B, %entry ], [ %incdec.ptr, %for.body ]
%conv = trunc i64 %i.02 to i32
%mul = mul nsw i64 %i.02, 3
%sub = add nsw i64 %mul, -5
%arrayidx1 = getelementptr inbounds [100 x i32]* %A, i64 %i.02, i64 %sub
store i32 %conv, i32* %arrayidx1, align 4
%arrayidx3 = getelementptr inbounds [100 x i32]* %A, i64 %i.02, i64 %i.02
%0 = load i32* %arrayidx3, align 4
; CHECK: da analyze - none!
%incdec.ptr = getelementptr inbounds i32* %B.addr.01, i64 1
store i32 %0, i32* %B.addr.01, align 4
%inc = add nsw i64 %i.02, 1
%cmp = icmp slt i64 %inc, 50
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
ret void
}
;; for (long int i = 0; i <= 15; i++)
;; A[3*i - 18][3 - i] = ...
;; ... = A[i][i]
define void @couple8([100 x i32]* %A, i32* %B, i32 %n) nounwind uwtable ssp {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.02 = phi i64 [ 0, %entry ], [ %inc, %for.body ]
%B.addr.01 = phi i32* [ %B, %entry ], [ %incdec.ptr, %for.body ]
%conv = trunc i64 %i.02 to i32
%sub = sub nsw i64 3, %i.02
%mul = mul nsw i64 %i.02, 3
%sub1 = add nsw i64 %mul, -18
%arrayidx2 = getelementptr inbounds [100 x i32]* %A, i64 %sub1, i64 %sub
store i32 %conv, i32* %arrayidx2, align 4
%arrayidx4 = getelementptr inbounds [100 x i32]* %A, i64 %i.02, i64 %i.02
%0 = load i32* %arrayidx4, align 4
; CHECK: da analyze - none!
%incdec.ptr = getelementptr inbounds i32* %B.addr.01, i64 1
store i32 %0, i32* %B.addr.01, align 4
%inc = add nsw i64 %i.02, 1
%cmp = icmp slt i64 %inc, 16
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
ret void
}
;; for (long int i = 0; i <= 15; i++)
;; A[3*i - 18][2 - i] = ...
;; ... = A[i][i]
define void @couple9([100 x i32]* %A, i32* %B, i32 %n) nounwind uwtable ssp {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.02 = phi i64 [ 0, %entry ], [ %inc, %for.body ]
%B.addr.01 = phi i32* [ %B, %entry ], [ %incdec.ptr, %for.body ]
%conv = trunc i64 %i.02 to i32
%sub = sub nsw i64 2, %i.02
%mul = mul nsw i64 %i.02, 3
%sub1 = add nsw i64 %mul, -18
%arrayidx2 = getelementptr inbounds [100 x i32]* %A, i64 %sub1, i64 %sub
store i32 %conv, i32* %arrayidx2, align 4
%arrayidx4 = getelementptr inbounds [100 x i32]* %A, i64 %i.02, i64 %i.02
%0 = load i32* %arrayidx4, align 4
; CHECK: da analyze - none!
%incdec.ptr = getelementptr inbounds i32* %B.addr.01, i64 1
store i32 %0, i32* %B.addr.01, align 4
%inc = add nsw i64 %i.02, 1
%cmp = icmp slt i64 %inc, 16
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
ret void
}
;; for (long int i = 0; i <= 15; i++)
;; A[3*i - 18][6 - i] = ...
;; ... = A[i][i]
define void @couple10([100 x i32]* %A, i32* %B, i32 %n) nounwind uwtable ssp {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.02 = phi i64 [ 0, %entry ], [ %inc, %for.body ]
%B.addr.01 = phi i32* [ %B, %entry ], [ %incdec.ptr, %for.body ]
%conv = trunc i64 %i.02 to i32
%sub = sub nsw i64 6, %i.02
%mul = mul nsw i64 %i.02, 3
%sub1 = add nsw i64 %mul, -18
%arrayidx2 = getelementptr inbounds [100 x i32]* %A, i64 %sub1, i64 %sub
store i32 %conv, i32* %arrayidx2, align 4
%arrayidx4 = getelementptr inbounds [100 x i32]* %A, i64 %i.02, i64 %i.02
%0 = load i32* %arrayidx4, align 4
; CHECK: da analyze - flow [>] splitable!
; CHECK: da analyze - split level = 1, iteration = 3!
%incdec.ptr = getelementptr inbounds i32* %B.addr.01, i64 1
store i32 %0, i32* %B.addr.01, align 4
%inc = add nsw i64 %i.02, 1
%cmp = icmp slt i64 %inc, 16
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
ret void
}
;; for (long int i = 0; i <= 15; i++)
;; A[3*i - 18][18 - i] = ...
;; ... = A[i][i]
define void @couple11([100 x i32]* %A, i32* %B, i32 %n) nounwind uwtable ssp {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.02 = phi i64 [ 0, %entry ], [ %inc, %for.body ]
%B.addr.01 = phi i32* [ %B, %entry ], [ %incdec.ptr, %for.body ]
%conv = trunc i64 %i.02 to i32
%sub = sub nsw i64 18, %i.02
%mul = mul nsw i64 %i.02, 3
%sub1 = add nsw i64 %mul, -18
%arrayidx2 = getelementptr inbounds [100 x i32]* %A, i64 %sub1, i64 %sub
store i32 %conv, i32* %arrayidx2, align 4
%arrayidx4 = getelementptr inbounds [100 x i32]* %A, i64 %i.02, i64 %i.02
%0 = load i32* %arrayidx4, align 4
; CHECK: da analyze - flow [=|<] splitable!
; CHECK: da analyze - split level = 1, iteration = 9!
%incdec.ptr = getelementptr inbounds i32* %B.addr.01, i64 1
store i32 %0, i32* %B.addr.01, align 4
%inc = add nsw i64 %i.02, 1
%cmp = icmp slt i64 %inc, 16
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
ret void
}
;; for (long int i = 0; i <= 12; i++)
;; A[3*i - 18][22 - i] = ...
;; ... = A[i][i]
define void @couple12([100 x i32]* %A, i32* %B, i32 %n) nounwind uwtable ssp {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.02 = phi i64 [ 0, %entry ], [ %inc, %for.body ]
%B.addr.01 = phi i32* [ %B, %entry ], [ %incdec.ptr, %for.body ]
%conv = trunc i64 %i.02 to i32
%sub = sub nsw i64 22, %i.02
%mul = mul nsw i64 %i.02, 3
%sub1 = add nsw i64 %mul, -18
%arrayidx2 = getelementptr inbounds [100 x i32]* %A, i64 %sub1, i64 %sub
store i32 %conv, i32* %arrayidx2, align 4
%arrayidx4 = getelementptr inbounds [100 x i32]* %A, i64 %i.02, i64 %i.02
%0 = load i32* %arrayidx4, align 4
; CHECK: da analyze - flow [<] splitable!
; CHECK: da analyze - split level = 1, iteration = 11!
%incdec.ptr = getelementptr inbounds i32* %B.addr.01, i64 1
store i32 %0, i32* %B.addr.01, align 4
%inc = add nsw i64 %i.02, 1
%cmp = icmp slt i64 %inc, 13
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
ret void
}
;; for (long int i = 0; i < 12; i++)
;; A[3*i - 18][22 - i] = ...
;; ... = A[i][i]
define void @couple13([100 x i32]* %A, i32* %B, i32 %n) nounwind uwtable ssp {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.02 = phi i64 [ 0, %entry ], [ %inc, %for.body ]
%B.addr.01 = phi i32* [ %B, %entry ], [ %incdec.ptr, %for.body ]
%conv = trunc i64 %i.02 to i32
%sub = sub nsw i64 22, %i.02
%mul = mul nsw i64 %i.02, 3
%sub1 = add nsw i64 %mul, -18
%arrayidx2 = getelementptr inbounds [100 x i32]* %A, i64 %sub1, i64 %sub
store i32 %conv, i32* %arrayidx2, align 4
%arrayidx4 = getelementptr inbounds [100 x i32]* %A, i64 %i.02, i64 %i.02
%0 = load i32* %arrayidx4, align 4
; CHECK: da analyze - none!
%incdec.ptr = getelementptr inbounds i32* %B.addr.01, i64 1
store i32 %0, i32* %B.addr.01, align 4
%inc = add nsw i64 %i.02, 1
%cmp = icmp slt i64 %inc, 12
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
ret void
}
;; for (long int i = 0; i < 100; i++)
;; A[3*i - 18][18 - i][i] = ...
;; ... = A[i][i][i]
define void @couple14([100 x [100 x i32]]* %A, i32* %B, i32 %n) nounwind uwtable ssp {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.02 = phi i64 [ 0, %entry ], [ %inc, %for.body ]
%B.addr.01 = phi i32* [ %B, %entry ], [ %incdec.ptr, %for.body ]
%conv = trunc i64 %i.02 to i32
%sub = sub nsw i64 18, %i.02
%mul = mul nsw i64 %i.02, 3
%sub1 = add nsw i64 %mul, -18
%arrayidx3 = getelementptr inbounds [100 x [100 x i32]]* %A, i64 %sub1, i64 %sub, i64 %i.02
store i32 %conv, i32* %arrayidx3, align 4
%arrayidx6 = getelementptr inbounds [100 x [100 x i32]]* %A, i64 %i.02, i64 %i.02, i64 %i.02
%0 = load i32* %arrayidx6, align 4
; CHECK: da analyze - flow [=|<] splitable!
; CHECK: da analyze - split level = 1, iteration = 9!
%incdec.ptr = getelementptr inbounds i32* %B.addr.01, i64 1
store i32 %0, i32* %B.addr.01, align 4
%inc = add nsw i64 %i.02, 1
%cmp = icmp slt i64 %inc, 100
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
ret void
}
;; for (long int i = 0; i < 100; i++)
;; A[3*i - 18][22 - i][i] = ...
;; ... = A[i][i][i]
define void @couple15([100 x [100 x i32]]* %A, i32* %B, i32 %n) nounwind uwtable ssp {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.02 = phi i64 [ 0, %entry ], [ %inc, %for.body ]
%B.addr.01 = phi i32* [ %B, %entry ], [ %incdec.ptr, %for.body ]
%conv = trunc i64 %i.02 to i32
%sub = sub nsw i64 22, %i.02
%mul = mul nsw i64 %i.02, 3
%sub1 = add nsw i64 %mul, -18
%arrayidx3 = getelementptr inbounds [100 x [100 x i32]]* %A, i64 %sub1, i64 %sub, i64 %i.02
store i32 %conv, i32* %arrayidx3, align 4
%arrayidx6 = getelementptr inbounds [100 x [100 x i32]]* %A, i64 %i.02, i64 %i.02, i64 %i.02
%0 = load i32* %arrayidx6, align 4
; CHECK: da analyze - none!
%incdec.ptr = getelementptr inbounds i32* %B.addr.01, i64 1
store i32 %0, i32* %B.addr.01, align 4
%inc = add nsw i64 %i.02, 1
%cmp = icmp slt i64 %inc, 100
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
ret void
}