; 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 }