no-widen-expensive.ll
1.37 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
; RUN: opt < %s -indvars -S | FileCheck %s
target triple = "nvptx64-unknown-unknown"
; For the nvptx64 architecture, the cost of an arithmetic instruction on a
; 64-bit integer is twice as expensive as that on a 32-bit integer, because the
; hardware needs to simulate a 64-bit integer using two 32-bit integers.
; Therefore, in this particular architecture, we should not widen induction
; variables to 64-bit integers even though i64 is a legal type in the 64-bit
; PTX ISA.
define void @indvar_32_bit(i32 %n, i32* nocapture %output) {
; CHECK-LABEL: @indvar_32_bit
entry:
%cmp5 = icmp sgt i32 %n, 0
br i1 %cmp5, label %for.body.preheader, label %for.end
for.body.preheader: ; preds = %entry
br label %for.body
for.body: ; preds = %for.body.preheader, %for.body
%i.06 = phi i32 [ 0, %for.body.preheader ], [ %add, %for.body ]
; CHECK: phi i32
%mul = mul nsw i32 %i.06, %i.06
%0 = sext i32 %i.06 to i64
%arrayidx = getelementptr inbounds i32, i32* %output, i64 %0
store i32 %mul, i32* %arrayidx, align 4
%add = add nsw i32 %i.06, 3
%cmp = icmp slt i32 %add, %n
br i1 %cmp, label %for.body, label %for.end.loopexit
for.end.loopexit: ; preds = %for.body
br label %for.end
for.end: ; preds = %for.end.loopexit, %entry
ret void
}