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llvm-project/llvm/test/Transforms/CodeGenPrepare/X86/select.ll

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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -codegenprepare -S < %s | FileCheck %s
; RUN: opt -debugify -codegenprepare -S < %s | FileCheck %s -check-prefix=DEBUG
target triple = "x86_64-unknown-unknown"
; Nothing to sink and convert here.
define i32 @no_sink(double %a, double* %b, i32 %x, i32 %y) {
; CHECK-LABEL: @no_sink(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[LOAD:%.*]] = load double, double* [[B:%.*]], align 8
; CHECK-NEXT: [[CMP:%.*]] = fcmp olt double [[LOAD]], [[A:%.*]]
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[CMP]], i32 [[X:%.*]], i32 [[Y:%.*]]
; CHECK-NEXT: ret i32 [[SEL]]
;
entry:
%load = load double, double* %b, align 8
%cmp = fcmp olt double %load, %a
%sel = select i1 %cmp, i32 %x, i32 %y
ret i32 %sel
}
; An 'fdiv' is expensive, so sink it rather than speculatively execute it.
define float @fdiv_true_sink(float %a, float %b) {
; CHECK-LABEL: @fdiv_true_sink(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[SEL_FR:%.*]] = freeze float [[A:%.*]]
; CHECK-NEXT: [[CMP:%.*]] = fcmp ogt float [[SEL_FR]], 1.000000e+00
; CHECK-NEXT: br i1 [[CMP]], label [[SELECT_TRUE_SINK:%.*]], label [[SELECT_END:%.*]]
; CHECK: select.true.sink:
; CHECK-NEXT: [[DIV:%.*]] = fdiv float [[A]], [[B:%.*]]
; CHECK-NEXT: br label [[SELECT_END]]
; CHECK: select.end:
; CHECK-NEXT: [[SEL:%.*]] = phi float [ [[DIV]], [[SELECT_TRUE_SINK]] ], [ 2.000000e+00, [[ENTRY:%.*]] ]
; CHECK-NEXT: ret float [[SEL]]
;
; DEBUG-LABEL: @fdiv_true_sink(
; DEBUG-NEXT: entry:
; DEBUG-NEXT: [[SEL_FR:%.*]] = freeze float [[A:%.*]]
; DEBUG-NEXT: [[CMP:%.*]] = fcmp ogt float [[SEL_FR]], 1.000000e+00, !dbg !24
; DEBUG-NEXT: call void @llvm.dbg.value(metadata i1 [[CMP]]
; DEBUG-NEXT: br i1 [[CMP]], label [[SELECT_TRUE_SINK:%.*]], label [[SELECT_END:%.*]], !dbg
; DEBUG: select.true.sink:
; DEBUG-NEXT: [[DIV:%.*]] = fdiv float [[A]], [[B:%.*]]
; DEBUG-NEXT: call void @llvm.dbg.value(metadata float [[DIV]]
; DEBUG-NEXT: br label [[SELECT_END]], !dbg
; DEBUG: select.end:
; DEBUG-NEXT: [[SEL:%.*]] = phi float [ [[DIV]], [[SELECT_TRUE_SINK]] ], [ 2.000000e+00, [[ENTRY:%.*]] ], !dbg
; DEBUG-NEXT: call void @llvm.dbg.value(metadata float [[SEL]]
; DEBUG-NEXT: ret float [[SEL]]
;
entry:
%div = fdiv float %a, %b
%cmp = fcmp ogt float %a, 1.0
%sel = select i1 %cmp, float %div, float 2.0
ret float %sel
}
define float @fdiv_false_sink(float %a, float %b) {
; CHECK-LABEL: @fdiv_false_sink(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[SEL_FR:%.*]] = freeze float [[A:%.*]]
; CHECK-NEXT: [[CMP:%.*]] = fcmp ogt float [[SEL_FR]], 3.000000e+00
; CHECK-NEXT: br i1 [[CMP]], label [[SELECT_END:%.*]], label [[SELECT_FALSE_SINK:%.*]]
; CHECK: select.false.sink:
; CHECK-NEXT: [[DIV:%.*]] = fdiv float [[A]], [[B:%.*]]
; CHECK-NEXT: br label [[SELECT_END]]
; CHECK: select.end:
; CHECK-NEXT: [[SEL:%.*]] = phi float [ 4.000000e+00, [[ENTRY:%.*]] ], [ [[DIV]], [[SELECT_FALSE_SINK]] ]
; CHECK-NEXT: ret float [[SEL]]
;
; DEBUG-LABEL: @fdiv_false_sink(
; DEBUG-NEXT: entry:
; DEBUG-NEXT: [[SEL_FR:%.*]] = freeze float [[A:%.*]]
; DEBUG-NEXT: [[CMP:%.*]] = fcmp ogt float [[SEL_FR]], 3.000000e+00, !dbg !33
; DEBUG-NEXT: call void @llvm.dbg.value(metadata i1 [[CMP]]
; DEBUG-NEXT: br i1 [[CMP]], label [[SELECT_END:%.*]], label [[SELECT_FALSE_SINK:%.*]], !dbg
; DEBUG: select.false.sink:
; DEBUG-NEXT: [[DIV:%.*]] = fdiv float [[A]], [[B:%.*]]
; DEBUG-NEXT: call void @llvm.dbg.value(metadata float [[DIV]]
; DEBUG-NEXT: br label [[SELECT_END]], !dbg
; DEBUG: select.end:
; DEBUG-NEXT: [[SEL:%.*]] = phi float [ 4.000000e+00, [[ENTRY:%.*]] ], [ [[DIV]], [[SELECT_FALSE_SINK]] ], !dbg
; DEBUG-NEXT: call void @llvm.dbg.value(metadata float [[SEL]]
; DEBUG-NEXT: ret float [[SEL]], !dbg
;
entry:
%div = fdiv float %a, %b
%cmp = fcmp ogt float %a, 3.0
%sel = select i1 %cmp, float 4.0, float %div
ret float %sel
}
define float @fdiv_both_sink(float %a, float %b) {
; CHECK-LABEL: @fdiv_both_sink(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[SEL_FR:%.*]] = freeze float [[A:%.*]]
; CHECK-NEXT: [[CMP:%.*]] = fcmp ogt float [[SEL_FR]], 5.000000e+00
; CHECK-NEXT: br i1 [[CMP]], label [[SELECT_TRUE_SINK:%.*]], label [[SELECT_FALSE_SINK:%.*]]
; CHECK: select.true.sink:
; CHECK-NEXT: [[DIV1:%.*]] = fdiv float [[A]], [[B:%.*]]
; CHECK-NEXT: br label [[SELECT_END:%.*]]
; CHECK: select.false.sink:
; CHECK-NEXT: [[DIV2:%.*]] = fdiv float [[B]], [[A]]
; CHECK-NEXT: br label [[SELECT_END]]
; CHECK: select.end:
; CHECK-NEXT: [[SEL:%.*]] = phi float [ [[DIV1]], [[SELECT_TRUE_SINK]] ], [ [[DIV2]], [[SELECT_FALSE_SINK]] ]
; CHECK-NEXT: ret float [[SEL]]
;
entry:
%div1 = fdiv float %a, %b
%div2 = fdiv float %b, %a
%cmp = fcmp ogt float %a, 5.0
%sel = select i1 %cmp, float %div1, float %div2
ret float %sel
}
; But if the select is marked unpredictable, then don't turn it into a branch.
define float @unpredictable_select(float %a, float %b) {
; CHECK-LABEL: @unpredictable_select(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[DIV:%.*]] = fdiv float [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: [[CMP:%.*]] = fcmp ogt float [[A]], 1.000000e+00
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[CMP]], float [[DIV]], float 2.000000e+00, !unpredictable !0
; CHECK-NEXT: ret float [[SEL]]
;
entry:
%div = fdiv float %a, %b
%cmp = fcmp ogt float %a, 1.0
%sel = select i1 %cmp, float %div, float 2.0, !unpredictable !0
ret float %sel
}
!0 = !{}
; An 'fadd' is not too expensive, so it's ok to speculate.
define float @fadd_no_sink(float %a, float %b) {
; CHECK-LABEL: @fadd_no_sink(
; CHECK-NEXT: [[ADD:%.*]] = fadd float [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: [[CMP:%.*]] = fcmp ogt float 6.000000e+00, [[A]]
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[CMP]], float [[ADD]], float 7.000000e+00
; CHECK-NEXT: ret float [[SEL]]
;
%add = fadd float %a, %b
%cmp = fcmp ogt float 6.0, %a
%sel = select i1 %cmp, float %add, float 7.0
ret float %sel
}
; Possible enhancement: sinkability is only calculated with the direct
; operand of the select, so we don't try to sink this. The fdiv cost is not
; taken into account.
define float @fdiv_no_sink(float %a, float %b) {
; CHECK-LABEL: @fdiv_no_sink(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[DIV:%.*]] = fdiv float [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: [[ADD:%.*]] = fadd float [[DIV]], [[B]]
; CHECK-NEXT: [[CMP:%.*]] = fcmp ogt float [[A]], 1.000000e+00
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[CMP]], float [[ADD]], float 8.000000e+00
; CHECK-NEXT: ret float [[SEL]]
;
entry:
%div = fdiv float %a, %b
%add = fadd float %div, %b
%cmp = fcmp ogt float %a, 1.0
%sel = select i1 %cmp, float %add, float 8.0
ret float %sel
}
; Do not transform the CFG if the select operands may have side effects.
declare i64* @bar(i32, i32, i32)
declare i64* @baz(i32, i32, i32)
define i64* @calls_no_sink(i32 %in) {
; CHECK-LABEL: @calls_no_sink(
; CHECK-NEXT: [[CALL1:%.*]] = call i64* @bar(i32 1, i32 2, i32 3)
; CHECK-NEXT: [[CALL2:%.*]] = call i64* @baz(i32 1, i32 2, i32 3)
; CHECK-NEXT: [[TOBOOL:%.*]] = icmp ne i32 [[IN:%.*]], 0
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[TOBOOL]], i64* [[CALL1]], i64* [[CALL2]]
; CHECK-NEXT: ret i64* [[SEL]]
;
%call1 = call i64* @bar(i32 1, i32 2, i32 3)
%call2 = call i64* @baz(i32 1, i32 2, i32 3)
%tobool = icmp ne i32 %in, 0
%sel = select i1 %tobool, i64* %call1, i64* %call2
ret i64* %sel
}
define i32 @sdiv_no_sink(i32 %a, i32 %b) {
; CHECK-LABEL: @sdiv_no_sink(
; CHECK-NEXT: [[DIV1:%.*]] = sdiv i32 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: [[DIV2:%.*]] = sdiv i32 [[B]], [[A]]
; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i32 [[A]], 5
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[CMP]], i32 [[DIV1]], i32 [[DIV2]]
; CHECK-NEXT: ret i32 [[SEL]]
;
%div1 = sdiv i32 %a, %b
%div2 = sdiv i32 %b, %a
%cmp = icmp sgt i32 %a, 5
%sel = select i1 %cmp, i32 %div1, i32 %div2
ret i32 %sel
}
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