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

313 lines
12 KiB
LLVM

; RUN: opt < %s -analyze -basicaa -da | FileCheck %s
; ModuleID = 'SymbolicRDIV.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 < n1; i++)
;; A[2*i + n1] = ...
;; for (long int j = 0; j < n2; j++)
;; ... = A[3*j + 3*n1];
define void @symbolicrdiv0(i32* %A, i32* %B, i64 %n1, i64 %n2) nounwind uwtable ssp {
entry:
%cmp4 = icmp eq i64 %n1, 0
br i1 %cmp4, label %for.cond1.preheader, label %for.body
for.cond1.preheader: ; preds = %for.body, %entry
%cmp21 = icmp eq i64 %n2, 0
br i1 %cmp21, label %for.end11, label %for.body4
for.body: ; preds = %for.body, %entry
%i.05 = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%conv = trunc i64 %i.05 to i32
%mul = shl nsw i64 %i.05, 1
%add = add i64 %mul, %n1
%arrayidx = getelementptr inbounds i32* %A, i64 %add
store i32 %conv, i32* %arrayidx, align 4
%inc = add nsw i64 %i.05, 1
%cmp = icmp ult i64 %inc, %n1
br i1 %cmp, label %for.body, label %for.cond1.preheader
for.body4: ; preds = %for.body4, %for.cond1.preheader
%j.03 = phi i64 [ %inc10, %for.body4 ], [ 0, %for.cond1.preheader ]
%B.addr.02 = phi i32* [ %incdec.ptr, %for.body4 ], [ %B, %for.cond1.preheader ]
%mul56 = add i64 %j.03, %n1
%add7 = mul i64 %mul56, 3
%arrayidx8 = getelementptr inbounds i32* %A, i64 %add7
%0 = load i32* %arrayidx8, align 4
; CHECK: da analyze - none!
%incdec.ptr = getelementptr inbounds i32* %B.addr.02, i64 1
store i32 %0, i32* %B.addr.02, align 4
%inc10 = add nsw i64 %j.03, 1
%cmp2 = icmp ult i64 %inc10, %n2
br i1 %cmp2, label %for.body4, label %for.end11
for.end11: ; preds = %for.body4, %for.cond1.preheader
ret void
}
;; for (long int i = 0; i < n1; i++)
;; A[2*i + 5*n2] = ...
;; for (long int j = 0; j < n2; j++)
;; ... = A[3*j + 2*n2];
define void @symbolicrdiv1(i32* %A, i32* %B, i64 %n1, i64 %n2) nounwind uwtable ssp {
entry:
%cmp4 = icmp eq i64 %n1, 0
br i1 %cmp4, label %for.cond2.preheader, label %for.body
for.cond2.preheader: ; preds = %for.body, %entry
%cmp31 = icmp eq i64 %n2, 0
br i1 %cmp31, label %for.end12, label %for.body5
for.body: ; preds = %for.body, %entry
%i.05 = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%conv = trunc i64 %i.05 to i32
%mul = shl nsw i64 %i.05, 1
%mul1 = mul i64 %n2, 5
%add = add i64 %mul, %mul1
%arrayidx = getelementptr inbounds i32* %A, i64 %add
store i32 %conv, i32* %arrayidx, align 4
%inc = add nsw i64 %i.05, 1
%cmp = icmp ult i64 %inc, %n1
br i1 %cmp, label %for.body, label %for.cond2.preheader
for.body5: ; preds = %for.body5, %for.cond2.preheader
%j.03 = phi i64 [ %inc11, %for.body5 ], [ 0, %for.cond2.preheader ]
%B.addr.02 = phi i32* [ %incdec.ptr, %for.body5 ], [ %B, %for.cond2.preheader ]
%mul6 = mul nsw i64 %j.03, 3
%mul7 = shl i64 %n2, 1
%add8 = add i64 %mul6, %mul7
%arrayidx9 = getelementptr inbounds i32* %A, i64 %add8
%0 = load i32* %arrayidx9, align 4
; CHECK: da analyze - none!
%incdec.ptr = getelementptr inbounds i32* %B.addr.02, i64 1
store i32 %0, i32* %B.addr.02, align 4
%inc11 = add nsw i64 %j.03, 1
%cmp3 = icmp ult i64 %inc11, %n2
br i1 %cmp3, label %for.body5, label %for.end12
for.end12: ; preds = %for.body5, %for.cond2.preheader
ret void
}
;; for (long int i = 0; i < n1; i++)
;; A[2*i - n2] = ...
;; for (long int j = 0; j < n2; j++)
;; ... = A[-j + 2*n1];
define void @symbolicrdiv2(i32* %A, i32* %B, i64 %n1, i64 %n2) nounwind uwtable ssp {
entry:
%cmp4 = icmp eq i64 %n1, 0
br i1 %cmp4, label %for.cond1.preheader, label %for.body
for.cond1.preheader: ; preds = %for.body, %entry
%cmp21 = icmp eq i64 %n2, 0
br i1 %cmp21, label %for.end10, label %for.body4
for.body: ; preds = %for.body, %entry
%i.05 = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%conv = trunc i64 %i.05 to i32
%mul = shl nsw i64 %i.05, 1
%sub = sub i64 %mul, %n2
%arrayidx = getelementptr inbounds i32* %A, i64 %sub
store i32 %conv, i32* %arrayidx, align 4
%inc = add nsw i64 %i.05, 1
%cmp = icmp ult i64 %inc, %n1
br i1 %cmp, label %for.body, label %for.cond1.preheader
for.body4: ; preds = %for.body4, %for.cond1.preheader
%j.03 = phi i64 [ %inc9, %for.body4 ], [ 0, %for.cond1.preheader ]
%B.addr.02 = phi i32* [ %incdec.ptr, %for.body4 ], [ %B, %for.cond1.preheader ]
%mul6 = shl i64 %n1, 1
%add = sub i64 %mul6, %j.03
%arrayidx7 = getelementptr inbounds i32* %A, i64 %add
%0 = load i32* %arrayidx7, align 4
; CHECK: da analyze - none!
%incdec.ptr = getelementptr inbounds i32* %B.addr.02, i64 1
store i32 %0, i32* %B.addr.02, align 4
%inc9 = add nsw i64 %j.03, 1
%cmp2 = icmp ult i64 %inc9, %n2
br i1 %cmp2, label %for.body4, label %for.end10
for.end10: ; preds = %for.body4, %for.cond1.preheader
ret void
}
;; for (long int i = 0; i < n1; i++)
;; A[-i + n2] = ...
;; for (long int j = 0; j < n2; j++)
;; ... = A[j - n1];
define void @symbolicrdiv3(i32* %A, i32* %B, i64 %n1, i64 %n2) nounwind uwtable ssp {
entry:
%cmp4 = icmp eq i64 %n1, 0
br i1 %cmp4, label %for.cond1.preheader, label %for.body
for.cond1.preheader: ; preds = %for.body, %entry
%cmp21 = icmp eq i64 %n2, 0
br i1 %cmp21, label %for.end9, label %for.body4
for.body: ; preds = %for.body, %entry
%i.05 = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%conv = trunc i64 %i.05 to i32
%add = sub i64 %n2, %i.05
%arrayidx = getelementptr inbounds i32* %A, i64 %add
store i32 %conv, i32* %arrayidx, align 4
%inc = add nsw i64 %i.05, 1
%cmp = icmp ult i64 %inc, %n1
br i1 %cmp, label %for.body, label %for.cond1.preheader
for.body4: ; preds = %for.body4, %for.cond1.preheader
%j.03 = phi i64 [ %inc8, %for.body4 ], [ 0, %for.cond1.preheader ]
%B.addr.02 = phi i32* [ %incdec.ptr, %for.body4 ], [ %B, %for.cond1.preheader ]
%sub5 = sub i64 %j.03, %n1
%arrayidx6 = getelementptr inbounds i32* %A, i64 %sub5
%0 = load i32* %arrayidx6, align 4
; CHECK: da analyze - none!
%incdec.ptr = getelementptr inbounds i32* %B.addr.02, i64 1
store i32 %0, i32* %B.addr.02, align 4
%inc8 = add nsw i64 %j.03, 1
%cmp2 = icmp ult i64 %inc8, %n2
br i1 %cmp2, label %for.body4, label %for.end9
for.end9: ; preds = %for.body4, %for.cond1.preheader
ret void
}
;; for (long int i = 0; i < n1; i++)
;; A[-i + 2*n1] = ...
;; for (long int j = 0; j < n2; j++)
;; ... = A[-j + n1];
define void @symbolicrdiv4(i32* %A, i32* %B, i64 %n1, i64 %n2) nounwind uwtable ssp {
entry:
%cmp4 = icmp eq i64 %n1, 0
br i1 %cmp4, label %for.cond1.preheader, label %for.body
for.cond1.preheader: ; preds = %for.body, %entry
%cmp21 = icmp eq i64 %n2, 0
br i1 %cmp21, label %for.end10, label %for.body4
for.body: ; preds = %for.body, %entry
%i.05 = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%conv = trunc i64 %i.05 to i32
%mul = shl i64 %n1, 1
%add = sub i64 %mul, %i.05
%arrayidx = getelementptr inbounds i32* %A, i64 %add
store i32 %conv, i32* %arrayidx, align 4
%inc = add nsw i64 %i.05, 1
%cmp = icmp ult i64 %inc, %n1
br i1 %cmp, label %for.body, label %for.cond1.preheader
for.body4: ; preds = %for.body4, %for.cond1.preheader
%j.03 = phi i64 [ %inc9, %for.body4 ], [ 0, %for.cond1.preheader ]
%B.addr.02 = phi i32* [ %incdec.ptr, %for.body4 ], [ %B, %for.cond1.preheader ]
%add6 = sub i64 %n1, %j.03
%arrayidx7 = getelementptr inbounds i32* %A, i64 %add6
%0 = load i32* %arrayidx7, align 4
; CHECK: da analyze - none!
%incdec.ptr = getelementptr inbounds i32* %B.addr.02, i64 1
store i32 %0, i32* %B.addr.02, align 4
%inc9 = add nsw i64 %j.03, 1
%cmp2 = icmp ult i64 %inc9, %n2
br i1 %cmp2, label %for.body4, label %for.end10
for.end10: ; preds = %for.body4, %for.cond1.preheader
ret void
}
;; for (long int i = 0; i < n1; i++)
;; A[-i + n2] = ...
;; for (long int j = 0; j < n2; j++)
;; ... = A[-j + 2*n2];
define void @symbolicrdiv5(i32* %A, i32* %B, i64 %n1, i64 %n2) nounwind uwtable ssp {
entry:
%cmp4 = icmp eq i64 %n1, 0
br i1 %cmp4, label %for.cond1.preheader, label %for.body
for.cond1.preheader: ; preds = %for.body, %entry
%cmp21 = icmp eq i64 %n2, 0
br i1 %cmp21, label %for.end10, label %for.body4
for.body: ; preds = %for.body, %entry
%i.05 = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%conv = trunc i64 %i.05 to i32
%add = sub i64 %n2, %i.05
%arrayidx = getelementptr inbounds i32* %A, i64 %add
store i32 %conv, i32* %arrayidx, align 4
%inc = add nsw i64 %i.05, 1
%cmp = icmp ult i64 %inc, %n1
br i1 %cmp, label %for.body, label %for.cond1.preheader
for.body4: ; preds = %for.body4, %for.cond1.preheader
%j.03 = phi i64 [ %inc9, %for.body4 ], [ 0, %for.cond1.preheader ]
%B.addr.02 = phi i32* [ %incdec.ptr, %for.body4 ], [ %B, %for.cond1.preheader ]
%mul = shl i64 %n2, 1
%add6 = sub i64 %mul, %j.03
%arrayidx7 = getelementptr inbounds i32* %A, i64 %add6
%0 = load i32* %arrayidx7, align 4
; CHECK: da analyze - none!
%incdec.ptr = getelementptr inbounds i32* %B.addr.02, i64 1
store i32 %0, i32* %B.addr.02, align 4
%inc9 = add nsw i64 %j.03, 1
%cmp2 = icmp ult i64 %inc9, %n2
br i1 %cmp2, label %for.body4, label %for.end10
for.end10: ; preds = %for.body4, %for.cond1.preheader
ret void
}
;; for (long int i = 0; i < n1; i++)
;; for (long int j = 0; j < n2; j++)
;; A[j -i + n2] = ...
;; ... = A[2*n2];
define void @symbolicrdiv6(i32* %A, i32* %B, i64 %n1, i64 %n2) nounwind uwtable ssp {
entry:
%cmp4 = icmp eq i64 %n1, 0
br i1 %cmp4, label %for.end7, label %for.cond1.preheader
for.cond1.preheader: ; preds = %for.inc5, %entry
%B.addr.06 = phi i32* [ %B.addr.1.lcssa, %for.inc5 ], [ %B, %entry ]
%i.05 = phi i64 [ %inc6, %for.inc5 ], [ 0, %entry ]
%cmp21 = icmp eq i64 %n2, 0
br i1 %cmp21, label %for.inc5, label %for.body3
for.body3: ; preds = %for.body3, %for.cond1.preheader
%j.03 = phi i64 [ %inc, %for.body3 ], [ 0, %for.cond1.preheader ]
%B.addr.12 = phi i32* [ %incdec.ptr, %for.body3 ], [ %B.addr.06, %for.cond1.preheader ]
%conv = trunc i64 %i.05 to i32
%sub = sub nsw i64 %j.03, %i.05
%add = add i64 %sub, %n2
%arrayidx = getelementptr inbounds i32* %A, i64 %add
store i32 %conv, i32* %arrayidx, align 4
%mul = shl i64 %n2, 1
%arrayidx4 = getelementptr inbounds i32* %A, i64 %mul
%0 = load i32* %arrayidx4, align 4
; CHECK: da analyze - none!
%incdec.ptr = getelementptr inbounds i32* %B.addr.12, i64 1
store i32 %0, i32* %B.addr.12, align 4
%inc = add nsw i64 %j.03, 1
%cmp2 = icmp ult i64 %inc, %n2
br i1 %cmp2, label %for.body3, label %for.inc5
for.inc5: ; preds = %for.body3, %for.cond1.preheader
%B.addr.1.lcssa = phi i32* [ %B.addr.06, %for.cond1.preheader ], [ %incdec.ptr, %for.body3 ]
%inc6 = add nsw i64 %i.05, 1
%cmp = icmp ult i64 %inc6, %n1
br i1 %cmp, label %for.cond1.preheader, label %for.end7
for.end7: ; preds = %for.inc5, %entry
ret void
}