1 ; RUN: llc -o - %s | FileCheck %s 2 ; This tests for the problem originally reported in http://llvm.org/PR25951 3 target triple = "i686-unknown-linux-gnu" 4 5 @b = common global i8 0, align 1 6 @c = common global i32 0, align 4 7 @a = common global i8 0, align 1 8 @d = common global i8 0, align 1 9 @.str = private unnamed_addr constant [4 x i8] c"%d\0A\00", align 1 10 11 ; CHECK-LABEL: func: 12 ; This tests whether eax is properly saved/restored around the lahf/sahf 13 ; instruction sequences. 14 define i32 @func() { 15 entry: 16 %bval = load i8, i8* @b 17 %inc = add i8 %bval, 1 18 store i8 %inc, i8* @b 19 %cval = load i32, i32* @c 20 %inc1 = add nsw i32 %cval, 1 21 store i32 %inc1, i32* @c 22 %aval = load i8, i8* @a 23 %inc2 = add i8 %aval, 1 24 store i8 %inc2, i8* @a 25 ; Copy flags produced by the incb of %inc1 to a register, need to save+restore 26 ; eax around it. The flags will be reused by %tobool. 27 ; CHECK: pushl %eax 28 ; CHECK: seto %al 29 ; CHECK: lahf 30 ; CHECK: movl %eax, [[REG:%[a-z]+]] 31 ; CHECK: popl %eax 32 %cmp = icmp eq i8 %aval, %bval 33 %conv5 = zext i1 %cmp to i8 34 store i8 %conv5, i8* @d 35 %tobool = icmp eq i32 %inc1, 0 36 ; We restore flags with an 'addb, sahf' sequence, need to save+restore eax 37 ; around it. 38 ; CHECK: pushl %eax 39 ; CHECK: movl [[REG]], %eax 40 ; CHECK: addb $127, %al 41 ; CHECK: sahf 42 ; CHECK: popl %eax 43 br i1 %tobool, label %if.end, label %if.then 44 45 if.then: 46 %conv6 = sext i8 %inc to i32 47 %call = tail call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i32 0, i32 0), i32 %conv6) 48 br label %if.end 49 50 if.end: 51 ret i32 0 52 } 53 54 declare i32 @printf(i8* nocapture readonly, ...) 55
