9791ed4705
Summary: http://reviews.llvm.org/D11212 made Scalar Evolution able to propagate NSW and NUW flags from instructions to SCEVs for add instructions. This patch expands that to sub, mul and shl instructions. This change makes LSR able to generate pointer induction variables for loops like these, where the index is 32 bit and the pointer is 64 bit: for (int i = 0; i < numIterations; ++i) sum += ptr[i - offset]; for (int i = 0; i < numIterations; ++i) sum += ptr[i * stride]; for (int i = 0; i < numIterations; ++i) sum += ptr[3 * (i << 7)]; Reviewers: atrick, sanjoy Subscribers: sanjoy, majnemer, hfinkel, llvm-commits, meheff, jingyue, eliben Differential Revision: http://reviews.llvm.org/D11860 llvm-svn: 245118
54 lines
1.8 KiB
LLVM
54 lines
1.8 KiB
LLVM
; RUN: opt -scalar-evolution -analyze < %s | FileCheck %s
|
|
;
|
|
; This checks if the min and max expressions are properly recognized by
|
|
; ScalarEvolution even though they the ICmpInst and SelectInst have different
|
|
; types.
|
|
;
|
|
; #define max(a, b) (a > b ? a : b)
|
|
; #define min(a, b) (a < b ? a : b)
|
|
;
|
|
; void f(int *A, int N) {
|
|
; for (int i = 0; i < N; i++) {
|
|
; A[max(0, i - 3)] = A[min(N, i + 3)] * 2;
|
|
; }
|
|
; }
|
|
;
|
|
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
|
|
|
|
define void @f(i32* %A, i32 %N) {
|
|
bb:
|
|
br label %bb1
|
|
|
|
bb1: ; preds = %bb2, %bb
|
|
%i.0 = phi i32 [ 0, %bb ], [ %tmp23, %bb2 ]
|
|
%i.0.1 = sext i32 %i.0 to i64
|
|
%tmp = icmp slt i32 %i.0, %N
|
|
br i1 %tmp, label %bb2, label %bb24
|
|
|
|
bb2: ; preds = %bb1
|
|
%tmp3 = add nuw nsw i32 %i.0, 3
|
|
%tmp4 = icmp slt i32 %tmp3, %N
|
|
%tmp5 = sext i32 %tmp3 to i64
|
|
%tmp6 = sext i32 %N to i64
|
|
%tmp9 = select i1 %tmp4, i64 %tmp5, i64 %tmp6
|
|
; min(N, i+3)
|
|
; CHECK: select i1 %tmp4, i64 %tmp5, i64 %tmp6
|
|
; CHECK-NEXT: --> (-1 + (-1 * ((-1 + (-1 * (sext i32 {3,+,1}<nw><%bb1> to i64))<nsw>) smax (-1 + (-1 * (sext i32 %N to i64))<nsw>)))<nsw>)
|
|
%tmp11 = getelementptr inbounds i32, i32* %A, i64 %tmp9
|
|
%tmp12 = load i32, i32* %tmp11, align 4
|
|
%tmp13 = shl nsw i32 %tmp12, 1
|
|
%tmp14 = icmp sge i32 3, %i.0
|
|
%tmp17 = add nsw i64 %i.0.1, -3
|
|
%tmp19 = select i1 %tmp14, i64 0, i64 %tmp17
|
|
; max(0, i - 3)
|
|
; CHECK: select i1 %tmp14, i64 0, i64 %tmp17
|
|
; CHECK-NEXT: --> (-3 + (3 smax {0,+,1}<nuw><nsw><%bb1>))
|
|
%tmp21 = getelementptr inbounds i32, i32* %A, i64 %tmp19
|
|
store i32 %tmp13, i32* %tmp21, align 4
|
|
%tmp23 = add nuw nsw i32 %i.0, 1
|
|
br label %bb1
|
|
|
|
bb24: ; preds = %bb1
|
|
ret void
|
|
}
|