; RUN: llc -mtriple=x86_64-pc-linux -x86-cmov-converter=true -verify-machineinstrs < %s | FileCheck %s ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; This test checks that x86-cmov-converter optimization does not transform CMOV ;; instruction when the gain (in cycles) of converting to branch is less than ;; a fix threshold (measured for "-x86-cmov-converter-threshold=4"). ;; ;; Test was created using the following command line: ;; > clang -S -O2 -m64 -fno-vectorize -fno-unroll-loops -emit-llvm foo.c -o - ;; Where foo.c is: ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;int bar(int *a, int *b, int n) { ;; int sum = 0; ;; for (int i = 0; i < n; ++i) { ;; int x = a[i] * a[i+1] * a[i+2]; ;; int y = b[i] * b[i+1]; ;; sum += y > x ? x : 0; ;; } ;; return sum; ;;} ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; Adding a test to the above function shows code with CMOV is 25% faster than ;; the code with branch. ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;#define N 10000 ;;int A[N]; ;;int B[N]; ;; ;; ;; ;;int main () { ;; for (int i=0; i< N; ++i) { ;; A[i] = i%4; ;; B[i] = i%5; ;; } ;; int sum = 0; ;; for (int i=0; i< N*10; ++i) ;; sum += bar(A, B, N); ;; return sum; ;;} ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; CHECK-NOT: jg ; CHECK: cmovle define i32 @bar(i32* nocapture readonly %a, i32* nocapture readonly %b, i32 %n) #0 { entry: %cmp30 = icmp sgt i32 %n, 0 br i1 %cmp30, label %for.body.preheader, label %for.cond.cleanup for.body.preheader: ; preds = %entry %.pre = load i32, i32* %a, align 4 %arrayidx2.phi.trans.insert = getelementptr inbounds i32, i32* %a, i64 1 %.pre34 = load i32, i32* %arrayidx2.phi.trans.insert, align 4 %.pre35 = load i32, i32* %b, align 4 %wide.trip.count = zext i32 %n to i64 br label %for.body for.cond.cleanup: ; preds = %for.body, %entry %sum.0.lcssa = phi i32 [ 0, %entry ], [ %add14, %for.body ] ret i32 %sum.0.lcssa for.body: ; preds = %for.body, %for.body.preheader %0 = phi i32 [ %.pre35, %for.body.preheader ], [ %5, %for.body ] %1 = phi i32 [ %.pre34, %for.body.preheader ], [ %4, %for.body ] %2 = phi i32 [ %.pre, %for.body.preheader ], [ %1, %for.body ] %indvars.iv = phi i64 [ 0, %for.body.preheader ], [ %indvars.iv.next, %for.body ] %sum.032 = phi i32 [ 0, %for.body.preheader ], [ %add14, %for.body ] %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 %mul = mul nsw i32 %1, %2 %3 = add nuw nsw i64 %indvars.iv, 2 %arrayidx5 = getelementptr inbounds i32, i32* %a, i64 %3 %4 = load i32, i32* %arrayidx5, align 4 %mul6 = mul nsw i32 %mul, %4 %arrayidx11 = getelementptr inbounds i32, i32* %b, i64 %indvars.iv.next %5 = load i32, i32* %arrayidx11, align 4 %mul12 = mul nsw i32 %5, %0 %cmp13 = icmp sgt i32 %mul12, %mul6 %cond = select i1 %cmp13, i32 %mul6, i32 0 %add14 = add nsw i32 %cond, %sum.032 %exitcond = icmp eq i64 %indvars.iv.next, %wide.trip.count br i1 %exitcond, label %for.cond.cleanup, label %for.body } attributes #0 = {"target-cpu"="skylake"} !llvm.module.flags = !{!0, !1} !llvm.ident = !{!2} !0 = !{i32 1, !"wchar_size", i32 2} !1 = !{i32 7, !"PIC Level", i32 2} !2 = !{!"clang version 5.0.0 (trunk)"}