[WebAssembly] Trapping fptoint builtins and intrinsics

Summary:
The WebAssembly backend lowers fptoint instructions to a code sequence
that checks for overflow to avoid traps because fptoint is supposed to
be speculatable. These new builtins and intrinsics give users a way to
depend on the trapping semantics of the underlying instructions and
avoid the extra code generated normally.

Patch by coffee and tlively.

Reviewers: aheejin

Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D68902

llvm-svn: 374856

3 files changed, 108 insertions, 0 deletions

diff --git a/llvm/include/llvm/IR/IntrinsicsWebAssembly.td b/llvm/include/llvm/IR/IntrinsicsWebAssembly.td
index ef5219b05bb..810979b9993 100644
--- a/llvm/include/llvm/IR/IntrinsicsWebAssembly.td
+++ b/llvm/include/llvm/IR/IntrinsicsWebAssembly.td
@@ -24,6 +24,17 @@ def int_wasm_memory_grow : Intrinsic<[llvm_anyint_ty],
                                      []>;
 
 //===----------------------------------------------------------------------===//
+// Trapping float-to-int conversions
+//===----------------------------------------------------------------------===//
+
+def int_wasm_trunc_signed : Intrinsic<[llvm_anyint_ty],
+                                      [llvm_anyfloat_ty],
+                                      [IntrNoMem]>;
+def int_wasm_trunc_unsigned : Intrinsic<[llvm_anyint_ty],
+                                        [llvm_anyfloat_ty],
+                                        [IntrNoMem]>;
+
+//===----------------------------------------------------------------------===//
 // Saturating float-to-int conversions
 //===----------------------------------------------------------------------===//
 
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyInstrConv.td b/llvm/lib/Target/WebAssembly/WebAssemblyInstrConv.td
index 661fee2715b..f3d9c5d5032 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyInstrConv.td
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyInstrConv.td
@@ -171,6 +171,23 @@ defm I64_TRUNC_U_F64 : I<(outs I64:$dst), (ins F64:$src), (outs), (ins),
                          0xb1>;
 } // hasSideEffects = 1
 
+def : Pat<(int_wasm_trunc_signed F32:$src),
+          (I32_TRUNC_S_F32 F32:$src)>;
+def : Pat<(int_wasm_trunc_unsigned F32:$src),
+          (I32_TRUNC_U_F32 F32:$src)>;
+def : Pat<(int_wasm_trunc_signed F64:$src),
+          (I32_TRUNC_S_F64 F64:$src)>;
+def : Pat<(int_wasm_trunc_unsigned F64:$src),
+          (I32_TRUNC_U_F64 F64:$src)>;
+def : Pat<(int_wasm_trunc_signed F32:$src),
+          (I64_TRUNC_S_F32 F32:$src)>;
+def : Pat<(int_wasm_trunc_unsigned F32:$src),
+          (I64_TRUNC_U_F32 F32:$src)>;
+def : Pat<(int_wasm_trunc_signed F64:$src),
+          (I64_TRUNC_S_F64 F64:$src)>;
+def : Pat<(int_wasm_trunc_unsigned F64:$src),
+          (I64_TRUNC_U_F64 F64:$src)>;
+
 defm F32_CONVERT_S_I32 : I<(outs F32:$dst), (ins I32:$src), (outs), (ins),
                            [(set F32:$dst, (sint_to_fp I32:$src))],
                            "f32.convert_i32_s\t$dst, $src", "f32.convert_i32_s",
diff --git a/llvm/test/CodeGen/WebAssembly/conv-trap.ll b/llvm/test/CodeGen/WebAssembly/conv-trap.ll
index eff10ff9ca0..67519ee68fd 100644
--- a/llvm/test/CodeGen/WebAssembly/conv-trap.ll
+++ b/llvm/test/CodeGen/WebAssembly/conv-trap.ll
@@ -165,3 +165,83 @@ define i64 @i64_trunc_u_f64(double %x) {
   %a = fptoui double %x to i64
   ret i64 %a
 }
+
+; CHECK-LABEL: llvm_wasm_trunc_signed_i32_f32:
+; CHECK-NEXT: .functype llvm_wasm_trunc_signed_i32_f32 (f32) -> (i32)
+; CHECK-NEXT: i32.trunc_f32_s $push[[L0:[0-9]+]]=, $0{{$}}
+; CHECK-NEXT: return $pop[[L0]]{{$}}
+declare i32 @llvm.wasm.trunc.signed.i32.f32(float)
+define i32 @llvm_wasm_trunc_signed_i32_f32(float %f) {
+  %a = call i32 @llvm.wasm.trunc.signed.i32.f32(float %f)
+  ret i32 %a
+}
+
+; CHECK-LABEL: llvm_wasm_trunc_unsigned_i32_f32:
+; CHECK-NEXT: .functype llvm_wasm_trunc_unsigned_i32_f32 (f32) -> (i32)
+; CHECK-NEXT: i32.trunc_f32_u $push[[L0:[0-9]+]]=, $0{{$}}
+; CHECK-NEXT: return $pop[[L0]]{{$}}
+declare i32 @llvm.wasm.trunc.unsigned.i32.f32(float)
+define i32 @llvm_wasm_trunc_unsigned_i32_f32(float %f) {
+  %a = call i32 @llvm.wasm.trunc.unsigned.i32.f32(float %f)
+  ret i32 %a
+}
+
+; CHECK-LABEL: llvm_wasm_trunc_signed_i32_f64:
+; CHECK-NEXT: .functype llvm_wasm_trunc_signed_i32_f64 (f64) -> (i32)
+; CHECK-NEXT: i32.trunc_f64_s $push[[L0:[0-9]+]]=, $0{{$}}
+; CHECK-NEXT: return $pop[[L0]]{{$}}
+declare i32 @llvm.wasm.trunc.signed.i32.f64(double)
+define i32 @llvm_wasm_trunc_signed_i32_f64(double %f) {
+  %a = call i32 @llvm.wasm.trunc.signed.i32.f64(double %f)
+  ret i32 %a
+}
+
+; CHECK-LABEL: llvm_wasm_trunc_unsigned_i32_f64:
+; CHECK-NEXT: .functype llvm_wasm_trunc_unsigned_i32_f64 (f64) -> (i32)
+; CHECK-NEXT: i32.trunc_f64_u $push[[L0:[0-9]+]]=, $0{{$}}
+; CHECK-NEXT: return $pop[[L0]]{{$}}
+declare i32 @llvm.wasm.trunc.unsigned.i32.f64(double)
+define i32 @llvm_wasm_trunc_unsigned_i32_f64(double %f) {
+  %a = call i32 @llvm.wasm.trunc.unsigned.i32.f64(double %f)
+  ret i32 %a
+}
+
+; CHECK-LABEL: llvm_wasm_trunc_signed_i64_f32:
+; CHECK-NEXT: .functype llvm_wasm_trunc_signed_i64_f32 (f32) -> (i64)
+; CHECK-NEXT: i64.trunc_f32_s $push[[L0:[0-9]+]]=, $0{{$}}
+; CHECK-NEXT: return $pop[[L0]]{{$}}
+declare i64 @llvm.wasm.trunc.signed.i64.f32(float)
+define i64 @llvm_wasm_trunc_signed_i64_f32(float %f) {
+  %a = call i64 @llvm.wasm.trunc.signed.i64.f32(float %f)
+  ret i64 %a
+}
+
+; CHECK-LABEL: llvm_wasm_trunc_unsigned_i64_f32:
+; CHECK-NEXT: .functype llvm_wasm_trunc_unsigned_i64_f32 (f32) -> (i64)
+; CHECK-NEXT: i64.trunc_f32_u $push[[L0:[0-9]+]]=, $0{{$}}
+; CHECK-NEXT: return $pop[[L0]]{{$}}
+declare i64 @llvm.wasm.trunc.unsigned.i64.f32(float)
+define i64 @llvm_wasm_trunc_unsigned_i64_f32(float %f) {
+  %a = call i64 @llvm.wasm.trunc.unsigned.i64.f32(float %f)
+  ret i64 %a
+}
+
+; CHECK-LABEL: llvm_wasm_trunc_signed_i64_f64:
+; CHECK-NEXT: .functype llvm_wasm_trunc_signed_i64_f64 (f64) -> (i64)
+; CHECK-NEXT: i64.trunc_f64_s $push[[L0:[0-9]+]]=, $0{{$}}
+; CHECK-NEXT: return $pop[[L0]]{{$}}
+declare i64 @llvm.wasm.trunc.signed.i64.f64(double)
+define i64 @llvm_wasm_trunc_signed_i64_f64(double %f) {
+  %a = call i64 @llvm.wasm.trunc.signed.i64.f64(double %f)
+  ret i64 %a
+}
+
+; CHECK-LABEL: llvm_wasm_trunc_unsigned_i64_f64:
+; CHECK-NEXT: .functype llvm_wasm_trunc_unsigned_i64_f64 (f64) -> (i64)
+; CHECK-NEXT: i64.trunc_f64_u $push[[L0:[0-9]+]]=, $0{{$}}
+; CHECK-NEXT: return $pop[[L0]]{{$}}
+declare i64 @llvm.wasm.trunc.unsigned.i64.f64(double)
+define i64 @llvm_wasm_trunc_unsigned_i64_f64(double %f) {
+  %a = call i64 @llvm.wasm.trunc.unsigned.i64.f64(double %f)
+  ret i64 %a
+}