2 files changed, 43 insertions, 23 deletions
diff --git a/llvm/test/Transforms/SimplifyCFG/X86/speculate-cttz-ctlz.ll b/llvm/test/Transforms/SimplifyCFG/X86/speculate-cttz-ctlz.ll
index bee80e6acce..69f6c69059d 100644
--- a/llvm/test/Transforms/SimplifyCFG/X86/speculate-cttz-ctlz.ll
+++ b/llvm/test/Transforms/SimplifyCFG/X86/speculate-cttz-ctlz.ll
@@ -7,7 +7,9 @@ define i64 @test1(i64 %A) {
 ; ALL-LABEL: @test1(
 ; ALL: [[COND:%[A-Za-z0-9]+]] = icmp eq i64 %A, 0
 ; ALL: [[CTLZ:%[A-Za-z0-9]+]] = tail call i64 @llvm.ctlz.i64(i64 %A, i1 true)
-; ALL-NEXT: select i1 [[COND]], i64 64, i64 [[CTLZ]]
+; LZCNT-NEXT: select i1 [[COND]], i64 64, i64 [[CTLZ]]
+; BMI-NOT: select
+; GENERIC-NOT: select
 ; ALL: ret
 entry:
   %tobool = icmp eq i64 %A, 0
@@ -26,7 +28,9 @@ define i32 @test2(i32 %A) {
 ; ALL-LABEL: @test2(
 ; ALL: [[COND:%[A-Za-z0-9]+]] = icmp eq i32 %A, 0
 ; ALL: [[CTLZ:%[A-Za-z0-9]+]] = tail call i32 @llvm.ctlz.i32(i32 %A, i1 true)
-; ALL-NEXT: select i1 [[COND]], i32 32, i32 [[CTLZ]]
+; LZCNT-NEXT: select i1 [[COND]], i32 32, i32 [[CTLZ]]
+; BMI-NOT: select
+; GENERIC-NOT: select
 ; ALL: ret
 entry:
   %tobool = icmp eq i32 %A, 0
@@ -46,7 +50,9 @@ define signext i16 @test3(i16 signext %A) {
 ; ALL-LABEL: @test3(
 ; ALL: [[COND:%[A-Za-z0-9]+]] = icmp eq i16 %A, 0
 ; ALL: [[CTLZ:%[A-Za-z0-9]+]] = tail call i16 @llvm.ctlz.i16(i16 %A, i1 true)
-; ALL-NEXT: select i1 [[COND]], i16 16, i16 [[CTLZ]]
+; LZCNT-NEXT: select i1 [[COND]], i16 16, i16 [[CTLZ]]
+; BMI-NOT: select
+; GENERIC-NOT: select
 ; ALL: ret
 entry:
   %tobool = icmp eq i16 %A, 0
@@ -66,7 +72,9 @@ define i64 @test1b(i64 %A) {
 ; ALL-LABEL: @test1b(
 ; ALL: [[COND:%[A-Za-z0-9]+]] = icmp eq i64 %A, 0
 ; ALL: [[CTTZ:%[A-Za-z0-9]+]] = tail call i64 @llvm.cttz.i64(i64 %A, i1 true)
-; ALL-NEXT: select i1 [[COND]], i64 64, i64 [[CTTZ]]
+; BMI-NEXT: select i1 [[COND]], i64 64, i64 [[CTTZ]]
+; LZCNT-NOT: select
+; GENERIC-NOT: select
 ; ALL: ret
 entry:
   %tobool = icmp eq i64 %A, 0
@@ -86,7 +94,9 @@ define i32 @test2b(i32 %A) {
 ; ALL-LABEL: @test2b(
 ; ALL: [[COND:%[A-Za-z0-9]+]] = icmp eq i32 %A, 0
 ; ALL: [[CTTZ:%[A-Za-z0-9]+]] = tail call i32 @llvm.cttz.i32(i32 %A, i1 true)
-; ALL-NEXT: select i1 [[COND]], i32 32, i32 [[CTTZ]]
+; BMI-NEXT: select i1 [[COND]], i32 32, i32 [[CTTZ]]
+; LZCNT-NOT: select
+; GENERIC-NOT: select
 ; ALL: ret
 entry:
   %tobool = icmp eq i32 %A, 0
@@ -106,7 +116,9 @@ define signext i16 @test3b(i16 signext %A) {
 ; ALL-LABEL: @test3b(
 ; ALL: [[COND:%[A-Za-z0-9]+]] = icmp eq i16 %A, 0
 ; ALL: [[CTTZ:%[A-Za-z0-9]+]] = tail call i16 @llvm.cttz.i16(i16 %A, i1 true)
-; ALL-NEXT: select i1 [[COND]], i16 16, i16 [[CTTZ]]
+; BMI-NEXT: select i1 [[COND]], i16 16, i16 [[CTTZ]]
+; LZCNT-NOT: select
+; GENERIC-NOT: select
 ; ALL: ret
 entry:
   %tobool = icmp eq i16 %A, 0
diff --git a/llvm/test/Transforms/SimplifyCFG/speculate-math.ll b/llvm/test/Transforms/SimplifyCFG/speculate-math.ll
index 5655d5d7882..442e8677e97 100644
--- a/llvm/test/Transforms/SimplifyCFG/speculate-math.ll
+++ b/llvm/test/Transforms/SimplifyCFG/speculate-math.ll
@@ -1,5 +1,4 @@
-; RUN: opt -S -simplifycfg < %s | FileCheck %s --check-prefix=EXPENSIVE --check-prefix=ALL
-; RUN: opt -S -simplifycfg -speculate-one-expensive-inst=false < %s | FileCheck %s --check-prefix=CHEAP --check-prefix=ALL
+; RUN: opt -S -simplifycfg -phi-node-folding-threshold=2 < %s | FileCheck %s
 
 declare float @llvm.sqrt.f32(float) nounwind readonly
 declare float @llvm.fma.f32(float, float, float) nounwind readonly
@@ -8,10 +7,19 @@ declare float @llvm.fabs.f32(float) nounwind readonly
 declare float @llvm.minnum.f32(float, float) nounwind readonly
 declare float @llvm.maxnum.f32(float, float) nounwind readonly
 
-; ALL-LABEL: @fdiv_test(
-; EXPENSIVE: select i1 %cmp, double %div, double 0.0
-; CHEAP-NOT: select
+; FIXME: This is intended to be a temporary test. As discussed in 
+; D12882, we actually do want to speculate even expensive operations
+; in SimplifyCFG because it can expose more optimizations for other
+; passes. Therefore, we either need to adjust SimplifyCFG's 
+; calculations that use the TTI cost model or use a different cost
+; model for deciding which ops should be speculated in SimplifyCFG. 
+; We should also be using the TTI cost model later - for example in
+; CodeGenPrepare - to potentially undo this speculation.
 
+; Do not speculate fdiv by default because it is generally expensive. 
+
+; CHECK-LABEL: @fdiv_test(
+; CHECK-NOT: select
 define double @fdiv_test(double %a, double %b) {
 entry:
   %cmp = fcmp ogt double %a, 0.0
@@ -26,8 +34,8 @@ cond.end:
   ret double %cond
 }
 
-; ALL-LABEL: @sqrt_test(
-; ALL: select
+; CHECK-LABEL: @sqrt_test(
+; CHECK: select
 define void @sqrt_test(float addrspace(1)* noalias nocapture %out, float %a) nounwind {
 entry:
   %cmp.i = fcmp olt float %a, 0.000000e+00
@@ -43,8 +51,8 @@ test_sqrt.exit:                                   ; preds = %cond.else.i, %entry
   ret void
 }
 
-; ALL-LABEL: @fabs_test(
-; ALL: select
+; CHECK-LABEL: @fabs_test(
+; CHECK: select
 define void @fabs_test(float addrspace(1)* noalias nocapture %out, float %a) nounwind {
 entry:
   %cmp.i = fcmp olt float %a, 0.000000e+00
@@ -60,8 +68,8 @@ test_fabs.exit:                                   ; preds = %cond.else.i, %entry
   ret void
 }
 
-; ALL-LABEL: @fma_test(
-; ALL: select
+; CHECK-LABEL: @fma_test(
+; CHECK: select
 define void @fma_test(float addrspace(1)* noalias nocapture %out, float %a, float %b, float %c) nounwind {
 entry:
   %cmp.i = fcmp olt float %a, 0.000000e+00
@@ -77,8 +85,8 @@ test_fma.exit:                                   ; preds = %cond.else.i, %entry
   ret void
 }
 
-; ALL-LABEL: @fmuladd_test(
-; ALL: select
+; CHECK-LABEL: @fmuladd_test(
+; CHECK: select
 define void @fmuladd_test(float addrspace(1)* noalias nocapture %out, float %a, float %b, float %c) nounwind {
 entry:
   %cmp.i = fcmp olt float %a, 0.000000e+00
@@ -94,8 +102,8 @@ test_fmuladd.exit:                                   ; preds = %cond.else.i, %en
   ret void
 }
 
-; ALL-LABEL: @minnum_test(
-; ALL: select
+; CHECK-LABEL: @minnum_test(
+; CHECK: select
 define void @minnum_test(float addrspace(1)* noalias nocapture %out, float %a, float %b) nounwind {
 entry:
   %cmp.i = fcmp olt float %a, 0.000000e+00
@@ -111,8 +119,8 @@ test_minnum.exit:                                   ; preds = %cond.else.i, %ent
   ret void
 }
 
-; ALL-LABEL: @maxnum_test(
-; ALL: select
+; CHECK-LABEL: @maxnum_test(
+; CHECK: select
 define void @maxnum_test(float addrspace(1)* noalias nocapture %out, float %a, float %b) nounwind {
 entry:
   %cmp.i = fcmp olt float %a, 0.000000e+00