diff options
Diffstat (limited to 'llvm/test/Transforms/CodeGenPrepare/X86/select.ll')
| -rw-r--r-- | llvm/test/Transforms/CodeGenPrepare/X86/select.ll | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/llvm/test/Transforms/CodeGenPrepare/X86/select.ll b/llvm/test/Transforms/CodeGenPrepare/X86/select.ll new file mode 100644 index 00000000000..7829376e9db --- /dev/null +++ b/llvm/test/Transforms/CodeGenPrepare/X86/select.ll @@ -0,0 +1,205 @@ +; 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: [[CMP:%.*]] = fcmp ogt float [[A:%.*]], 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: [[CMP:%.*]] = fcmp ogt float [[A:%.*]], 1.000000e+00 +; 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: [[CMP:%.*]] = fcmp ogt float [[A:%.*]], 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: [[CMP:%.*]] = fcmp ogt float [[A:%.*]], 3.000000e+00 +; 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: [[CMP:%.*]] = fcmp ogt float [[A:%.*]], 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 +} + |
