xref: /llvm-project/llvm/test/CodeGen/X86/pre-coalesce.ll (revision 2f448bf509432c1a19ec46ab8cbc7353c03c6280)
1; RUN: llc -regalloc=greedy -mtriple=x86_64-unknown-linux-gnu  < %s -o - | FileCheck %s
2;
3; The test is to check no redundent mov as follows will be generated in %while.body loop.
4;  .LBB0_2:
5;    movsbl	%cl, %ecx
6;    movl	%edx, %eax   ==> This movl can be promoted outside of loop.
7;    shll	$5, %eax
8;    ...
9;    movl	%eax, %edx
10;    jne     .LBB0_2
11;
12; CHECK-LABEL: foo:
13; CHECK: [[L0:.LBB0_[0-9]+]]: # %while.body
14; CHECK: movl %[[REGA:.*]], %[[REGB:.*]]
15; CHECK-NOT: movl %[[REGB]], %[[REGA]]
16; CHECK: jne [[L0]]
17;
18target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
19
20@b = common local_unnamed_addr global ptr null, align 8
21@a = common local_unnamed_addr global i32 0, align 4
22
23define i32 @foo() local_unnamed_addr {
24entry:
25  %t0 = load ptr, ptr @b, align 8
26  %t1 = load i8, ptr %t0, align 1
27  %cmp4 = icmp eq i8 %t1, 0
28  %t2 = load i32, ptr @a, align 4
29  br i1 %cmp4, label %while.end, label %while.body.preheader
30
31while.body.preheader:                             ; preds = %entry
32  br label %while.body
33
34while.body:                                       ; preds = %while.body.preheader, %while.body
35  %t3 = phi i32 [ %add3, %while.body ], [ %t2, %while.body.preheader ]
36  %t4 = phi i8 [ %t5, %while.body ], [ %t1, %while.body.preheader ]
37  %conv = sext i8 %t4 to i32
38  %add = mul i32 %t3, 33
39  %add3 = add nsw i32 %add, %conv
40  store i32 %add3, ptr @a, align 4
41  %t5 = load i8, ptr %t0, align 1
42  %cmp = icmp eq i8 %t5, 0
43  br i1 %cmp, label %while.end.loopexit, label %while.body
44
45while.end.loopexit:                               ; preds = %while.body
46  br label %while.end
47
48while.end:                                        ; preds = %while.end.loopexit, %entry
49  %.lcssa = phi i32 [ %t2, %entry ], [ %add3, %while.end.loopexit ]
50  ret i32 %.lcssa
51}
52