multiselect.ll
2.05 KB
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; Test that multiple select statements using the same condition are expanded
; into a single conditional branch when possible.
;
; RUN: llc < %s -mtriple=s390x-linux-gnu -disable-block-placement | FileCheck %s
define void @test0(i32 signext %positive, double %base, double %offset, double* %rmin, double* %rmax) {
entry:
; CHECK-LABEL: test0
; CHECK: cijlh %r2, 0,
; CHECK-NOT: cij
; CHECK-NOT: je
; CHECK-NOT: jlh
%tobool = icmp eq i32 %positive, 0
%add = fadd double %base, %offset
%min = select i1 %tobool, double %add, double %base
%max = select i1 %tobool, double %base, double %add
store double %min, double* %rmin, align 8
store double %max, double* %rmax, align 8
ret void
}
; Two selects with an intervening instruction that doesn't clobber CC can
; still be merged.
define double @test1(i32 signext %positive, double %A, double %B, double %C) {
entry:
; CHECK-LABEL: test1
; CHECK: cijhe {{.*}}LBB1_2
; CHECK-NOT: cij
; CHECK: br %r14
%tobool = icmp slt i32 %positive, 0
%s1 = select i1 %tobool, double %A, double %B
%mul = fmul double %A, %B
%s2 = select i1 %tobool, double %B, double %C
%add = fadd double %s1, %s2
%add2 = fadd double %add, %mul
ret double %add2
}
; Two selects with an intervening user of the first select can't be merged.
define double @test2(i32 signext %positive, double %A, double %B) {
entry:
; CHECK-LABEL: test2
; CHECK: cije {{.*}}LBB2_2
; CHECK: cibe {{.*}}%r14
; CHECK: br %r14
%tobool = icmp eq i32 %positive, 0
%s1 = select i1 %tobool, double %A, double %B
%add = fadd double %A, %s1
%s2 = select i1 %tobool, double %A, double %add
ret double %s2
}
; Two selects with different conditions can't be merged
define double @test3(i32 signext %positive, double %A, double %B, double %C) {
entry:
; CHECK-LABEL: test3
; CHECK: cijl {{.*}}LBB3_2
; CHECK: cijl {{.*}}LBB3_4
; CHECK: br %r14
%tobool = icmp slt i32 %positive, 0
%s1 = select i1 %tobool, double %A, double %B
%tobool2 = icmp slt i32 %positive, 2
%s2 = select i1 %tobool2, double %B, double %C
%add = fadd double %s1, %s2
ret double %add
}