From 11c6bab704a0f82f59dcb2f409f7d6ac3b1821f1 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Fri, 27 Nov 2009 19:11:31 +0000 Subject: add support for recursive phi translation and phi translation of add with immediate. This allows us to optimize this function: void test(int N, double* G) { long j; G[1] = 1; for (j = 1; j < N - 1; j++) G[j+1] = G[j] + G[j+1]; } to only do one load every iteration of the loop. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90013 91177308-0d34-0410-b5e6-96231b3b80d8 --- test/Transforms/GVN/pre-load.ll | 43 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) (limited to 'test') diff --git a/test/Transforms/GVN/pre-load.ll b/test/Transforms/GVN/pre-load.ll index 672adaaaeb..19ea8720d3 100644 --- a/test/Transforms/GVN/pre-load.ll +++ b/test/Transforms/GVN/pre-load.ll @@ -195,6 +195,49 @@ return: ret void } +;void test7(int N, double* G) { +; long j; +; G[1] = 1; +; for (j = 1; j < N - 1; j++) +; G[j+1] = G[j] + G[j+1]; +;} + +; This requires phi translation of the adds. +define void @test7(i32 %N, double* nocapture %G) nounwind ssp { +entry: + %0 = getelementptr inbounds double* %G, i64 1 + store double 1.000000e+00, double* %0, align 8 + %1 = add i32 %N, -1 + %2 = icmp sgt i32 %1, 1 + br i1 %2, label %bb.nph, label %return + +bb.nph: + %tmp = sext i32 %1 to i64 + %tmp7 = add i64 %tmp, -1 + br label %bb + +bb: + %indvar = phi i64 [ 0, %bb.nph ], [ %tmp9, %bb ] + %tmp8 = add i64 %indvar, 2 + %scevgep = getelementptr double* %G, i64 %tmp8 + %tmp9 = add i64 %indvar, 1 + %scevgep10 = getelementptr double* %G, i64 %tmp9 + %3 = load double* %scevgep10, align 8 + %4 = load double* %scevgep, align 8 + %5 = fadd double %3, %4 + store double %5, double* %scevgep, align 8 + %exitcond = icmp eq i64 %tmp9, %tmp7 + br i1 %exitcond, label %return, label %bb + +; Should only be one load in the loop. +; CHECK: bb: +; CHECK: load double* +; CHECK-NOT: load double* +; CHECK: br i1 %exitcond + +return: + ret void +} ;;; --- todo -- cgit v1.2.3