[Cranelift] add imm64 abs/min/max helpers

Author: bongjunj

cranelift/codegen/src/isle_prelude.rs

@@ -137,6 +137,57 @@ macro_rules! isle_common_prelude_methods {
             Imm64::new(x.bits().wrapping_neg() & ty_mask)
         }
 
+        #[inline]
+        fn imm64_abs(&mut self, ty: Type, x: Imm64) -> Option<Imm64> {
+            let type_width = ty.bits();
+            assert!(type_width <= 64);
+
+            let x = x.sign_extend_from_width(type_width).bits();
+            let shift = 64 - type_width;
+            let min = ((self.ty_smin(ty) as i64) << shift) >> shift;
+            if x == min {
+                return None;
+            }
+
+            Some(Imm64::new(x.abs()).mask_to_width(type_width))
+        }
+
+        #[inline]
+        fn imm64_umin(&mut self, ty: Type, x: Imm64, y: Imm64) -> Imm64 {
+            let ty_mask = self.ty_mask(ty);
+            let x_u = (x.bits() as u64) & ty_mask;
+            let y_u = (y.bits() as u64) & ty_mask;
+            Imm64::new((if x_u <= y_u { x_u } else { y_u }) as i64)
+        }
+
+        #[inline]
+        fn imm64_umax(&mut self, ty: Type, x: Imm64, y: Imm64) -> Imm64 {
+            let ty_mask = self.ty_mask(ty);
+            let x_u = (x.bits() as u64) & ty_mask;
+            let y_u = (y.bits() as u64) & ty_mask;
+            Imm64::new((if x_u >= y_u { x_u } else { y_u }) as i64)
+        }
+
+        #[inline]
+        fn imm64_smin(&mut self, ty: Type, x: Imm64, y: Imm64) -> Imm64 {
+            let type_width = ty.bits();
+            assert!(type_width <= 64);
+            let x_s = x.sign_extend_from_width(type_width).bits();
+            let y_s = y.sign_extend_from_width(type_width).bits();
+            let selected = if x_s <= y_s { x_s } else { y_s };
+            Imm64::new(selected).mask_to_width(type_width)
+        }
+
+        #[inline]
+        fn imm64_smax(&mut self, ty: Type, x: Imm64, y: Imm64) -> Imm64 {
+            let type_width = ty.bits();
+            assert!(type_width <= 64);
+            let x_s = x.sign_extend_from_width(type_width).bits();
+            let y_s = y.sign_extend_from_width(type_width).bits();
+            let selected = if x_s >= y_s { x_s } else { y_s };
+            Imm64::new(selected).mask_to_width(type_width)
+        }
+
         #[inline]
         fn imm64_shl(&mut self, ty: Type, x: Imm64, y: Imm64) -> Imm64 {
             // Mask off any excess shift bits.

cranelift/codegen/src/prelude.isle

@@ -100,6 +100,21 @@
 (decl pure imm64_neg (Type Imm64) Imm64)
 (extern constructor imm64_neg imm64_neg)
 
+(decl pure partial imm64_abs (Type Imm64) Imm64)
+(extern constructor imm64_abs imm64_abs)
+
+(decl pure imm64_umin (Type Imm64 Imm64) Imm64)
+(extern constructor imm64_umin imm64_umin)
+
+(decl pure imm64_umax (Type Imm64 Imm64) Imm64)
+(extern constructor imm64_umax imm64_umax)
+
+(decl pure imm64_smin (Type Imm64 Imm64) Imm64)
+(extern constructor imm64_smin imm64_smin)
+
+(decl pure imm64_smax (Type Imm64 Imm64) Imm64)
+(extern constructor imm64_smax imm64_smax)
+
 (decl pure imm64_shl (Type Imm64 Imm64) Imm64)
 (extern constructor imm64_shl imm64_shl)