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; RUN: llc < %s -mtriple=powerpc64le-unknown-linux-gnu -verify-machineinstrs -mcpu=pwr8 | FileCheck %s --check-prefixes=CHECK,CHECK-PWR8
; Verify that we do NOT generate the mtctr instruction for loop trip counts < 4
; The latency of the mtctr is only justified if there are more than 4 comparisons that are removed as a result.
@a = local_unnamed_addr global i32 0, align 4
@b = local_unnamed_addr global i32 0, align 4
@c = local_unnamed_addr global i32 0, align 4
@d = local_unnamed_addr global i32 0, align 4
@e = local_unnamed_addr global i32 0, align 4
@f = local_unnamed_addr global i32 0, align 4
@arr = local_unnamed_addr global [5 x i32] zeroinitializer, align 4
; Function Attrs: norecurse nounwind readonly
define signext i32 @testTripCount2(i32 signext %a) {
; CHECK-LABEL: testTripCount2:
; CHECK-NOT: mtctr
; CHECK: blr
entry:
br label %for.body
for.cond.cleanup: ; preds = %for.body
ret i32 %add
for.body: ; preds = %entry, %for.body
%indvars.iv = phi i64 [ 1, %entry ], [ %indvars.iv.next, %for.body ]
%Sum.05 = phi i32 [ 0, %entry ], [ %add, %for.body ]
%arrayidx = getelementptr inbounds [5 x i32], ptr @arr, i64 0, i64 %indvars.iv
%0 = load i32, ptr %arrayidx, align 4
%add = add nsw i32 %0, %Sum.05
%indvars.iv.next = add nsw i64 %indvars.iv, -1
%tobool = icmp eq i64 %indvars.iv, 0
br i1 %tobool, label %for.cond.cleanup, label %for.body
}
; Function Attrs: norecurse nounwind readonly
define signext i32 @testTripCount3(i32 signext %a) {
; CHECK-LABEL: testTripCount3:
; CHECK-NOT: mtctr
; CHECK: blr
entry:
br label %for.body
for.cond.cleanup: ; preds = %for.body
ret i32 %add
for.body: ; preds = %entry, %for.body
%indvars.iv = phi i64 [ 2, %entry ], [ %indvars.iv.next, %for.body ]
%Sum.05 = phi i32 [ 0, %entry ], [ %add, %for.body ]
%arrayidx = getelementptr inbounds [5 x i32], ptr @arr, i64 0, i64 %indvars.iv
%0 = load i32, ptr %arrayidx, align 4
%add = add nsw i32 %0, %Sum.05
%indvars.iv.next = add nsw i64 %indvars.iv, -1
%tobool = icmp eq i64 %indvars.iv, 0
br i1 %tobool, label %for.cond.cleanup, label %for.body
}
; Function Attrs: norecurse nounwind readonly
define signext i32 @testTripCount4(i32 signext %a) {
; CHECK-LABEL: testTripCount4:
; CHECK: mtctr
; CHECK: bdnz
entry:
br label %for.body
for.cond.cleanup: ; preds = %for.body
ret i32 %add
for.body: ; preds = %entry, %for.body
%indvars.iv = phi i64 [ 3, %entry ], [ %indvars.iv.next, %for.body ]
%Sum.05 = phi i32 [ 0, %entry ], [ %add, %for.body ]
%arrayidx = getelementptr inbounds [5 x i32], ptr @arr, i64 0, i64 %indvars.iv
%0 = load i32, ptr %arrayidx, align 4
%add = add nsw i32 %0, %Sum.05
%indvars.iv.next = add nsw i64 %indvars.iv, -1
%tobool = icmp eq i64 %indvars.iv, 0
br i1 %tobool, label %for.cond.cleanup, label %for.body
}
; Function Attrs: norecurse nounwind
define signext i32 @testTripCount2NonSmallLoop() {
; CHECK-LABEL: testTripCount2NonSmallLoop:
; CHECK-PWR8-NOT: mtctr
; CHECK: blr
entry:
%.pre = load i32, ptr @a, align 4
br label %for.body
for.body: ; preds = %entry, %if.end
%0 = phi i32 [ %.pre, %entry ], [ %1, %if.end ]
%dec4 = phi i32 [ 1, %entry ], [ %dec, %if.end ]
%b.03 = phi i8 [ 0, %entry ], [ %b.1, %if.end ]
%tobool1 = icmp eq i32 %0, 0
br i1 %tobool1, label %if.end, label %if.then
if.then: ; preds = %for.body
store i32 2, ptr @a, align 4
br label %if.end
if.end: ; preds = %for.body, %if.then
%1 = phi i32 [ 2, %if.then ], [ 0, %for.body ]
%b.1 = phi i8 [ 2, %if.then ], [ %b.03, %for.body ]
%dec = add nsw i32 %dec4, -1
%tobool = icmp eq i32 %dec4, 0
br i1 %tobool, label %for.end, label %for.body
for.end: ; preds = %if.end
%conv = zext i8 %b.1 to i32
ret i32 %conv
}
define signext i32 @testTripCount5() {
; CHECK-LABEL: testTripCount5:
; CHECK-PWR8-NOT: mtctr
entry:
%.prea = load i32, ptr @a, align 4
%.preb = load i32, ptr @b, align 4
%.prec = load i32, ptr @c, align 4
%.pred = load i32, ptr @d, align 4
%.pree = load i32, ptr @e, align 4
%.pref = load i32, ptr @f, align 4
br label %for.body
for.body: ; preds = %entry, %for.body
%indvars.iv = phi i64 [ 2, %entry ], [ %indvars.iv.next, %for.body ]
%0 = phi i32 [ %.prea, %entry ], [ %6, %for.body ]
%1 = phi i32 [ %.preb, %entry ], [ %7, %for.body ]
%2 = phi i32 [ %.prec, %entry ], [ %8, %for.body ]
%3 = phi i32 [ %.pred, %entry ], [ %9, %for.body ]
%4 = phi i32 [ %.pree, %entry ], [ %10, %for.body ]
%5 = phi i32 [ %.pref, %entry ], [ %11, %for.body ]
%6 = add i32 %0, 1
%7 = add i32 %1, 1
%8 = add i32 %2, 1
%9 = add i32 %3, 1
%10 = add i32 %4, 1
%11 = add i32 %5, 1
%indvars.iv.next = add nsw i64 %indvars.iv, -1
%tobool = icmp eq i64 %indvars.iv, 0
br i1 %tobool, label %for.end, label %for.body
for.end: ; preds = %for.body
store i32 %6, ptr @a, align 4
store i32 %7, ptr @b, align 4
store i32 %8, ptr @c, align 4
store i32 %9, ptr @d, align 4
store i32 %10, ptr @e, align 4
store i32 %11, ptr @f, align 4
ret i32 0
}
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