WebAssembly: floating-point comparisons

[jfb]

Summary

D11924 implemented part of the floating-point comparisons, this patch implements the rest:

• Tell ISelLowering that all booleans are either 0 or 1.
• Expand the eq/ne/lt/le/gt/ge floating-point comparisons to the canonical ones (similar to what Mips32r6InstrInfo.td does).
• Add tests for ord/uno.
• Add tests for ueq/one/ult/ule/ugt/uge.
• Fix existing comparison tests to remove the (res & 1) code, which setBooleanContents stops from generating.

[sunfish]

lib/Target/WebAssembly/WebAssemblyInstrFloat.td

39

"32-bit" is clear from the code so isn't really critical to have in a comment. The thing not immediately obvious is that these are the "don't care" operators, and what's happening here is that we're mapping "don't care" operators onto supported operators.

[jfb]

• Change comment.

lib/Target/WebAssembly/WebAssemblyISelLowering.cpp

 };
 
 int DiagnosticInfoUnsupported::KindID = 0;
 } // end anonymous namespace
 
 WebAssemblyTargetLowering::WebAssemblyTargetLowering(
     const TargetMachine &TM, const WebAssemblySubtarget &STI)
     : TargetLowering(TM), Subtarget(&STI) {
+  // Booleans always contain 0 or 1.
+  setBooleanContents(ZeroOrOneBooleanContent);
   // WebAssembly does not produce floating-point exceptions on normal floating
   // point operations.
   setHasFloatingPointExceptions(false);
   // We don't know the microarchitecture here, so just reduce register pressure.
   setSchedulingPreference(Sched::RegPressure);
   // Tell ISel that we have a stack pointer.
   setStackPointerRegisterToSaveRestore(
       Subtarget->hasAddr64() ? WebAssembly::SP64 : WebAssembly::SP32);

lib/Target/WebAssembly/WebAssemblyInstrFloat.td

 
 defm EQ : ComparisonFP<SETOEQ>;
 defm NE : ComparisonFP<SETUNE>;
 defm LT : ComparisonFP<SETOLT>;
 defm LE : ComparisonFP<SETOLE>;
 defm GT : ComparisonFP<SETOGT>;
 defm GE : ComparisonFP<SETOGE>;
 
+// Floating-point comparisons supported via other comparisons.
+// 32-bit:
+def : Pat<(seteq f32:$lhs, f32:$rhs), (EQ_F32 f32:$lhs, f32:$rhs)>;
+def : Pat<(setne f32:$lhs, f32:$rhs), (NE_F32 f32:$lhs, f32:$rhs)>;
+def : Pat<(setlt f32:$lhs, f32:$rhs), (LT_F32 f32:$lhs, f32:$rhs)>;
+def : Pat<(setle f32:$lhs, f32:$rhs), (LE_F32 f32:$lhs, f32:$rhs)>;
+def : Pat<(setgt f32:$lhs, f32:$rhs), (GT_F32 f32:$lhs, f32:$rhs)>;
+def : Pat<(setge f32:$lhs, f32:$rhs), (GE_F32 f32:$lhs, f32:$rhs)>;
+// 64-bit:
+def : Pat<(seteq f64:$lhs, f64:$rhs), (EQ_F64 f64:$lhs, f64:$rhs)>;
+def : Pat<(setne f64:$lhs, f64:$rhs), (NE_F64 f64:$lhs, f64:$rhs)>;
+def : Pat<(setlt f64:$lhs, f64:$rhs), (LT_F64 f64:$lhs, f64:$rhs)>;
+def : Pat<(setle f64:$lhs, f64:$rhs), (LE_F64 f64:$lhs, f64:$rhs)>;
+def : Pat<(setgt f64:$lhs, f64:$rhs), (GT_F64 f64:$lhs, f64:$rhs)>;
+def : Pat<(setge f64:$lhs, f64:$rhs), (GE_F64 f64:$lhs, f64:$rhs)>;
+
 defm SQRT : UnaryFP<fsqrt>;
 
 /*
  * TODO(jfb): Add the following for 32-bit and 64-bit.
  *
  * float32.min: minimum (binary operator); if either operand is NaN, returns NaN
  * float32.max: maximum (binary operator); if either operand is NaN, returns NaN
  */

test/CodeGen/WebAssembly/comparisons_f32.ll

 ; RUN: llc < %s -asm-verbose=false | FileCheck %s
 
 ; Test that basic 32-bit floating-point comparison operations assemble as
 ; expected.
 
 target datalayout = "e-p:32:32-i64:64-v128:8:128-n32:64-S128"
 target triple = "wasm32-unknown-unknown"
 
-; FIXME: add ord and uno tests.
+; CHECK-LABEL: ord_f32:
+; CHECK-NEXT: (setlocal @0 (argument 0))
+; CHECK-NEXT: (setlocal @1 (argument 1))
+; CHECK-NEXT: (setlocal @2 (eq @1 @1))
+; CHECK-NEXT: (setlocal @3 (eq @0 @0))
+; CHECK-NEXT: (setlocal @4 (and @3 @2))
+; CHECK-NEXT: (return @4)
+define i32 @ord_f32(float %x, float %y) {
+  %a = fcmp ord float %x, %y
+  %b = zext i1 %a to i32
+  ret i32 %b
+}
+
+; CHECK-LABEL: uno_f32:
+; CHECK-NEXT: (setlocal @0 (argument 0))
+; CHECK-NEXT: (setlocal @1 (argument 1))
+; CHECK-NEXT: (setlocal @2 (ne @1 @1))
+; CHECK-NEXT: (setlocal @3 (ne @0 @0))
+; CHECK-NEXT: (setlocal @4 (ior @3 @2))
+; CHECK-NEXT: (return @4)
+define i32 @uno_f32(float %x, float %y) {
+  %a = fcmp uno float %x, %y
+  %b = zext i1 %a to i32
+  ret i32 %b
+}
 
 ; CHECK-LABEL: oeq_f32:
 ; CHECK-NEXT: (setlocal @0 (argument 1))
 ; CHECK-NEXT: (setlocal @1 (argument 0))
 ; CHECK-NEXT: (setlocal @2 (eq @1 @0))
-; CHECK-NEXT: (setlocal @3 (immediate 1))
-; CHECK-NEXT: (setlocal @4 (and @2 @3))
-; CHECK-NEXT: (return @4)
+; CHECK-NEXT: (return @2)
 define i32 @oeq_f32(float %x, float %y) {
   %a = fcmp oeq float %x, %y
   %b = zext i1 %a to i32
   ret i32 %b
 }
 
 ; CHECK-LABEL: une_f32:
 ; CHECK: (setlocal @2 (ne @1 @0))

 ; CHECK-LABEL: oge_f32:
 ; CHECK: (setlocal @2 (ge @1 @0))
 define i32 @oge_f32(float %x, float %y) {
   %a = fcmp oge float %x, %y
   %b = zext i1 %a to i32
   ret i32 %b
 }
 
-; FIXME test other FP comparisons: ueq, one, ult, ule, ugt, uge. They currently
-; are broken and failt to match.
+; Expanded comparisons, which also check for NaN.
+
+; CHECK-LABEL: ueq_f32:
+; CHECK-NEXT: (setlocal @0 (argument 1))
+; CHECK-NEXT: (setlocal @1 (argument 0))
+; CHECK-NEXT: (setlocal @2 (eq @1 @0))
+; CHECK-NEXT: (setlocal @3 (ne @0 @0))
+; CHECK-NEXT: (setlocal @4 (ne @1 @1))
+; CHECK-NEXT: (setlocal @5 (ior @4 @3))
+; CHECK-NEXT: (setlocal @6 (ior @2 @5))
+; CHECK-NEXT: (return @6)
+define i32 @ueq_f32(float %x, float %y) {
+  %a = fcmp ueq float %x, %y
+  %b = zext i1 %a to i32
+  ret i32 %b
+}
+
+; CHECK-LABEL: one_f32:
+; CHECK: (setlocal @2 (ne @1 @0))
+define i32 @one_f32(float %x, float %y) {
+  %a = fcmp one float %x, %y
+  %b = zext i1 %a to i32
+  ret i32 %b
+}
+
+; CHECK-LABEL: ult_f32:
+; CHECK: (setlocal @2 (lt @1 @0))
+define i32 @ult_f32(float %x, float %y) {
+  %a = fcmp ult float %x, %y
+  %b = zext i1 %a to i32
+  ret i32 %b
+}
+
+; CHECK-LABEL: ule_f32:
+; CHECK: (setlocal @2 (le @1 @0))
+define i32 @ule_f32(float %x, float %y) {
+  %a = fcmp ule float %x, %y
+  %b = zext i1 %a to i32
+  ret i32 %b
+}
+
+; CHECK-LABEL: ugt_f32:
+; CHECK: (setlocal @2 (gt @1 @0))
+define i32 @ugt_f32(float %x, float %y) {
+  %a = fcmp ugt float %x, %y
+  %b = zext i1 %a to i32
+  ret i32 %b
+}
+
+; CHECK-LABEL: uge_f32:
+; CHECK: (setlocal @2 (ge @1 @0))
+define i32 @uge_f32(float %x, float %y) {
+  %a = fcmp uge float %x, %y
+  %b = zext i1 %a to i32
+  ret i32 %b
+}

test/CodeGen/WebAssembly/comparisons_f64.ll

 ; RUN: llc < %s -asm-verbose=false | FileCheck %s
 
 ; Test that basic 64-bit floating-point comparison operations assemble as
 ; expected.
 
 target datalayout = "e-p:32:32-i64:64-v128:8:128-n32:64-S128"
 target triple = "wasm32-unknown-unknown"
 
-; FIXME: add ord and uno tests.
+; CHECK-LABEL: ord_f64:
+; CHECK-NEXT: (setlocal @0 (argument 0))
+; CHECK-NEXT: (setlocal @1 (argument 1))
+; CHECK-NEXT: (setlocal @2 (eq @1 @1))
+; CHECK-NEXT: (setlocal @3 (eq @0 @0))
+; CHECK-NEXT: (setlocal @4 (and @3 @2))
+; CHECK-NEXT: (return @4)
+define i32 @ord_f64(double %x, double %y) {
+  %a = fcmp ord double %x, %y
+  %b = zext i1 %a to i32
+  ret i32 %b
+}
+
+; CHECK-LABEL: uno_f64:
+; CHECK-NEXT: (setlocal @0 (argument 0))
+; CHECK-NEXT: (setlocal @1 (argument 1))
+; CHECK-NEXT: (setlocal @2 (ne @1 @1))
+; CHECK-NEXT: (setlocal @3 (ne @0 @0))
+; CHECK-NEXT: (setlocal @4 (ior @3 @2))
+; CHECK-NEXT: (return @4)
+define i32 @uno_f64(double %x, double %y) {
+  %a = fcmp uno double %x, %y
+  %b = zext i1 %a to i32
+  ret i32 %b
+}
 
 ; CHECK-LABEL: oeq_f64:
 ; CHECK-NEXT: (setlocal @0 (argument 1))
 ; CHECK-NEXT: (setlocal @1 (argument 0))
 ; CHECK-NEXT: (setlocal @2 (eq @1 @0))
-; CHECK-NEXT: (setlocal @3 (immediate 1))
-; CHECK-NEXT: (setlocal @4 (and @2 @3))
-; CHECK-NEXT: (return @4)
+; CHECK-NEXT: (return @2)
 define i32 @oeq_f64(double %x, double %y) {
   %a = fcmp oeq double %x, %y
   %b = zext i1 %a to i32
   ret i32 %b
 }
 
 ; CHECK-LABEL: une_f64:
 ; CHECK: (setlocal @2 (ne @1 @0))

 ; CHECK-LABEL: oge_f64:
 ; CHECK: (setlocal @2 (ge @1 @0))
 define i32 @oge_f64(double %x, double %y) {
   %a = fcmp oge double %x, %y
   %b = zext i1 %a to i32
   ret i32 %b
 }
 
-; FIXME test other FP comparisons: ueq, one, ult, ule, ugt, uge. They currently
-; are broken and failt to match.
+; Expanded comparisons, which also check for NaN.
+
+; CHECK-LABEL: ueq_f64:
+; CHECK-NEXT: (setlocal @0 (argument 1))
+; CHECK-NEXT: (setlocal @1 (argument 0))
+; CHECK-NEXT: (setlocal @2 (eq @1 @0))
+; CHECK-NEXT: (setlocal @3 (ne @0 @0))
+; CHECK-NEXT: (setlocal @4 (ne @1 @1))
+; CHECK-NEXT: (setlocal @5 (ior @4 @3))
+; CHECK-NEXT: (setlocal @6 (ior @2 @5))
+; CHECK-NEXT: (return @6)
+define i32 @ueq_f64(double %x, double %y) {
+  %a = fcmp ueq double %x, %y
+  %b = zext i1 %a to i32
+  ret i32 %b
+}
+
+; CHECK-LABEL: one_f64:
+; CHECK: (setlocal @2 (ne @1 @0))
+define i32 @one_f64(double %x, double %y) {
+  %a = fcmp one double %x, %y
+  %b = zext i1 %a to i32
+  ret i32 %b
+}
+
+; CHECK-LABEL: ult_f64:
+; CHECK: (setlocal @2 (lt @1 @0))
+define i32 @ult_f64(double %x, double %y) {
+  %a = fcmp ult double %x, %y
+  %b = zext i1 %a to i32
+  ret i32 %b
+}
+
+; CHECK-LABEL: ule_f64:
+; CHECK: (setlocal @2 (le @1 @0))
+define i32 @ule_f64(double %x, double %y) {
+  %a = fcmp ule double %x, %y
+  %b = zext i1 %a to i32
+  ret i32 %b
+}
+
+; CHECK-LABEL: ugt_f64:
+; CHECK: (setlocal @2 (gt @1 @0))
+define i32 @ugt_f64(double %x, double %y) {
+  %a = fcmp ugt double %x, %y
+  %b = zext i1 %a to i32
+  ret i32 %b
+}
+
+; CHECK-LABEL: uge_f64:
+; CHECK: (setlocal @2 (ge @1 @0))
+define i32 @uge_f64(double %x, double %y) {
+  %a = fcmp uge double %x, %y
+  %b = zext i1 %a to i32
+  ret i32 %b
+}

test/CodeGen/WebAssembly/comparisons_i32.ll

 ; RUN: llc < %s -asm-verbose=false | FileCheck %s
 
 ; Test that basic 32-bit integer comparison operations assemble as expected.
 
 target datalayout = "e-p:32:32-i64:64-v128:8:128-n32:64-S128"
 target triple = "wasm32-unknown-unknown"
 
 ; CHECK-LABEL: eq_i32:
 ; CHECK-NEXT: (setlocal @0 (argument 1))
 ; CHECK-NEXT: (setlocal @1 (argument 0))
 ; CHECK-NEXT: (setlocal @2 (eq @1 @0))
-; CHECK-NEXT: (setlocal @3 (immediate 1))
-; CHECK-NEXT: (setlocal @4 (and @2 @3))
-; CHECK-NEXT: (return @4)
+; CHECK-NEXT: (return @2)
 define i32 @eq_i32(i32 %x, i32 %y) {
   %a = icmp eq i32 %x, %y
   %b = zext i1 %a to i32
   ret i32 %b
 }
 
 ; CHECK-LABEL: ne_i32:
 ; CHECK: (setlocal @2 (ne @1 @0))

test/CodeGen/WebAssembly/comparisons_i64.ll

 ; RUN: llc < %s -asm-verbose=false | FileCheck %s
 
 ; Test that basic 64-bit integer comparison operations assemble as expected.
 
 target datalayout = "e-p:32:32-i64:64-v128:8:128-n32:64-S128"
 target triple = "wasm32-unknown-unknown"
 
 ; CHECK-LABEL: eq_i64:
 ; CHECK-NEXT: (setlocal @0 (argument 1))
 ; CHECK-NEXT: (setlocal @1 (argument 0))
 ; CHECK-NEXT: (setlocal @2 (eq @1 @0))
-; CHECK-NEXT: (setlocal @3 (immediate 1))
-; CHECK-NEXT: (setlocal @4 (and @2 @3))
-; CHECK-NEXT: (return @4)
+; CHECK-NEXT: (return @2)
 define i32 @eq_i64(i64 %x, i64 %y) {
   %a = icmp eq i64 %x, %y
   %b = zext i1 %a to i32
   ret i32 %b
 }
 
 ; CHECK-LABEL: ne_i64:
 ; CHECK: (setlocal @2 (ne @1 @0))