cmd/compile: absorb InvertFlags into Noov comparisons

randall77 · randall77 · commit fb5bdb4cc94d · 2023-09-07T15:14:39.000Z
Unfortunately, there isn't a single op that provides the resulting computation. At least, I couldn't find one. Fixes #62469 Change-Id: I236f3965b827aaeb3d70ef9fe89be66b116494f5 Reviewed-on: https://go-review.googlesource.com/c/go/+/526276 LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Keith Randall <khr@google.com>
diff --git a/src/cmd/compile/internal/ssa/_gen/ARM64.rules b/src/cmd/compile/internal/ssa/_gen/ARM64.rules
@@ -1555,20 +1555,22 @@
 (GreaterEqualU (FlagConstant [fc])) => (MOVDconst [b2i(fc.uge())])
 
 // absorb InvertFlags into boolean values
-(Equal         (InvertFlags x)) => (Equal x)
-(NotEqual      (InvertFlags x)) => (NotEqual x)
-(LessThan      (InvertFlags x)) => (GreaterThan x)
-(LessThanU     (InvertFlags x)) => (GreaterThanU x)
-(GreaterThan   (InvertFlags x)) => (LessThan x)
-(GreaterThanU  (InvertFlags x)) => (LessThanU x)
-(LessEqual     (InvertFlags x)) => (GreaterEqual x)
-(LessEqualU    (InvertFlags x)) => (GreaterEqualU x)
-(GreaterEqual  (InvertFlags x)) => (LessEqual x)
-(GreaterEqualU (InvertFlags x)) => (LessEqualU x)
-(LessThanF     (InvertFlags x)) => (GreaterThanF x)
-(LessEqualF    (InvertFlags x)) => (GreaterEqualF x)
-(GreaterThanF  (InvertFlags x)) => (LessThanF x)
-(GreaterEqualF (InvertFlags x)) => (LessEqualF x)
+(Equal            (InvertFlags x)) => (Equal x)
+(NotEqual         (InvertFlags x)) => (NotEqual x)
+(LessThan         (InvertFlags x)) => (GreaterThan x)
+(LessThanU        (InvertFlags x)) => (GreaterThanU x)
+(GreaterThan      (InvertFlags x)) => (LessThan x)
+(GreaterThanU     (InvertFlags x)) => (LessThanU x)
+(LessEqual        (InvertFlags x)) => (GreaterEqual x)
+(LessEqualU       (InvertFlags x)) => (GreaterEqualU x)
+(GreaterEqual     (InvertFlags x)) => (LessEqual x)
+(GreaterEqualU    (InvertFlags x)) => (LessEqualU x)
+(LessThanF        (InvertFlags x)) => (GreaterThanF x)
+(LessEqualF       (InvertFlags x)) => (GreaterEqualF x)
+(GreaterThanF     (InvertFlags x)) => (LessThanF x)
+(GreaterEqualF    (InvertFlags x)) => (LessEqualF x)
+(LessThanNoov     (InvertFlags x)) => (BIC (GreaterEqualNoov <typ.Bool> x) (Equal <typ.Bool> x))
+(GreaterEqualNoov (InvertFlags x)) => (OR (LessThanNoov <typ.Bool> x) (Equal <typ.Bool> x))
 
 // Boolean-generating instructions (NOTE: NOT all boolean Values) always
 // zero upper bit of the register; no need to zero-extend
diff --git a/src/cmd/compile/internal/ssa/rewriteARM64.go b/src/cmd/compile/internal/ssa/rewriteARM64.go
diff --git a/test/fixedbugs/issue62469.go b/test/fixedbugs/issue62469.go
@@ -0,0 +1,15 @@
+// compile
+
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+func sign(p1, p2, p3 point) bool {
+	return (p1.x-p3.x)*(p2.y-p3.y)-(p2.x-p3.x)*(p1.y-p3.y) < 0
+}
+
+type point struct {
+	x, y int
+}
