fixes

Author: KGrewal1

cranelift/codegen/src/isle_prelude.rs

@@ -40,10 +40,11 @@ macro_rules! isle_common_prelude_methods {
         #[inline]
         fn imm64_sdiv(&mut self, ty: Type, x: Imm64, y: Imm64) -> Option<Imm64> {
             // Sign extend `x` and `y`.
-            assert!(ty.bits() <= 64);
-            let shift = 64 - ty.bits();
-            let x = (x.bits() << shift) >> shift;
-            let y = (y.bits() << shift) >> shift;
+            let type_width = ty.bits();
+            assert!(type_width <= 64);
+            let x = x.sign_extend_from_width(type_width).bits();
+            let y = y.sign_extend_from_width(type_width).bits();
+            let shift = 64 - type_width;
 
             // NB: We can't rely on `checked_div` to detect `ty::MIN / -1`
             // (which overflows and should trap) because we are working with
@@ -55,20 +56,20 @@ macro_rules! isle_common_prelude_methods {
                 return None;
             }
 
-            let ty_mask = self.ty_mask(ty) as i64;
-            let result = x.checked_div(y)? & ty_mask;
-            Some(Imm64::new(result))
+            let result = x.checked_div(y)?;
+            Some(Imm64::new(result).mask_to_width(type_width))
         }
 
         #[inline]
         fn imm64_srem(&mut self, ty: Type, x: Imm64, y: Imm64) -> Option<Imm64> {
             // Sign extend `x` and `y`.
-            assert!(ty.bits() <= 64);
-            let shift = 64 - ty.bits();
-            let x = (x.bits() << shift) >> shift;
-            let y = (y.bits() << shift) >> shift;
+            let type_width = ty.bits();
+            assert!(type_width <= 64);
+            let x = x.sign_extend_from_width(type_width).bits();
+            let y = y.sign_extend_from_width(type_width).bits();
+            let shift = 64 - type_width;
 
-            // NB: We can't rely on `checked_rem` to detect `ty::MIN / -1`
+            // NB: We can't rely on `checked_div` to detect `ty::MIN / -1`
             // (which overflows and should trap) because we are working with
             // `i64` values here, and `i32::MIN != i64::MIN`, for
             // example. Therefore, we have to explicitly check for this case
@@ -78,9 +79,8 @@ macro_rules! isle_common_prelude_methods {
                 return None;
             }
 
-            let ty_mask = self.ty_mask(ty) as i64;
-            let result = x.checked_rem(y)? & ty_mask;
-            Some(Imm64::new(result))
+            let result = x.checked_rem(y)?;
+            Some(Imm64::new(result).mask_to_width(type_width))
         }
 
         #[inline]

cranelift/codegen/src/opts/arithmetic.isle

@@ -125,7 +125,6 @@
 ;; x % 1 == 0
 (rule (simplify_skeleton (urem x (iconst_u ty 1))) (iconst_u ty 0))
 (rule (simplify_skeleton (srem x (iconst_u ty 1))) (iconst_u ty 0))
-(rule (simplify_skeleton (srem x (iconst_s ty -1))) (iconst_u ty 0))
 
 ;; Unsigned `x % d == x & ((1 << ilog2(d)) - 1)` when `d` is a power of two.
 (rule (simplify_skeleton (urem x (iconst_u ty (u64_extract_power_of_two d))))
@@ -339,5 +338,3 @@
 ;; (x + y) - y --> x
 (rule (simplify (isub ty (iadd ty x y) x)) y)
 (rule (simplify (isub ty (iadd ty x y) y)) x)
-
-

cranelift/codegen/src/opts/cprop.isle

@@ -31,13 +31,13 @@
 
 (rule (simplify_skeleton
        (sdiv (iconst ty k1)
-             (iconst _ k2)))
+             (iconst ty k2)))
       (if-let d (imm64_sdiv ty k1 k2))
       (iconst ty d))
 
 (rule (simplify_skeleton
        (srem (iconst ty k1)
-             (iconst _ k2)))
+             (iconst ty k2)))
       (if-let d (imm64_srem ty k1 k2))
       (iconst ty d))
 

cranelift/filetests/filetests/egraph/skeleton.clif

@@ -125,6 +125,54 @@ block0:
 ;     return v11  ; v11 = -1
 ; }
 
+function %cprop_sdiv_i8_min() -> i8 {
+block0:
+    v0 = iconst.i8 -128
+    v1 = iconst.i8 -1
+    v2 = sdiv v0, v1
+    return v2
+}
+
+;function %cprop_sdiv_i8_min() -> i8 fast {
+;block0:
+;     v0 = iconst.i8 -128
+;     v1 = iconst.i8 -1
+;     v2 = sdiv v0, v1  ; v0 = -128, v1 = -1
+;     return v2
+;}
+
+function %cprop_srem_i8_min() -> i8 {
+block0:
+    v0 = iconst.i8 -128
+    v1 = iconst.i8 -1
+    v2 = srem v0, v1
+    return v2
+}
+
+;function %cprop_srem_i8_min() -> i8 fast {
+;block0:
+;     v0 = iconst.i8 -128
+;     v1 = iconst.i8 -1
+;     v2 = srem v0, v1  ; v0 = -128, v1 = -1
+;     return v2
+;}
+
+function %cprop_srem_i64_min() -> i64 {
+block0:
+    v0 = iconst.i64 -9223372036854775808
+    v1 = iconst.i64 -1
+    v2 = srem v0, v1
+    return v2
+}
+
+;function %cprop_srem_i64_min() -> i64 fast {
+;block0:
+;     v0 = iconst.i64 -9223372036854775808
+;     v1 = iconst.i64 -1
+;     v2 = srem v0, v1  ; v0 = -9223372036854775808, v1 = -1
+;     return v2
+;}
+
 function %cprop_srem() -> i32 {
 block0:
     v0 = iconst.i32 -17
@@ -140,6 +188,7 @@ block0:
 ;     return v28  ; v28 = -3
 ; }
 
+
 function %udiv_by_one(i32) -> i32 {
 block0(v0: i32):
     v1 = iconst.i32 1