Share minor powers with float cache

Author: JairusSW

std/assembly/util/dtoa.ts

@@ -206,7 +206,13 @@ import { DIGITS, MAX_DOUBLE_LENGTH } from "./number";
   let j = i + 10;
   let major = (j * 293) >>> 13; // exact j / 28 for j in [10,627]
   let minor = j - major * 28;
-  let m = load<u64>(POW10_MINOR + (<usize>minor << 3));
+  let m: u64;
+  if (ASC_OPTIMIZE_LEVEL >= 3 && ASC_SHRINK_LEVEL == 0) {
+    // The minor factors are POW10_FLOAT_HI[44..17] in reverse order.
+    m = load<u64>(POW10_FLOAT_HI + (<usize>(44 - minor) << 3));
+  } else {
+    m = load<u64>(POW10_MINOR + (<usize>minor << 3));
+  }
   let hoff = POW10_MAJOR + (<usize>major << 4);
   let hHi = load<u64>(hoff);
   let hLo = load<u64>(hoff, 8);

tests/compiler/issues/2873.debug.wat

@@ -5944,6 +5944,10 @@
         i32.mul
         i32.sub
         local.set $minor
+        i32.const 0
+        i32.const 3
+        i32.ge_s
+        drop
         i32.const 1808
         local.get $minor
         i32.const 3
@@ -6348,6 +6352,10 @@
        i32.mul
        i32.sub
        local.set $minor|105
+       i32.const 0
+       i32.const 3
+       i32.ge_s
+       drop
        i32.const 1808
        local.get $minor|105
        i32.const 3
@@ -6954,6 +6962,10 @@
           i32.mul
           i32.sub
           local.set $minor|199
+          i32.const 0
+          i32.const 3
+          i32.ge_s
+          drop
           i32.const 1808
           local.get $minor|199
           i32.const 3
@@ -7358,6 +7370,10 @@
          i32.mul
          i32.sub
          local.set $minor|245
+         i32.const 0
+         i32.const 3
+         i32.ge_s
+         drop
          i32.const 1808
          local.get $minor|245
          i32.const 3
@@ -7956,6 +7972,10 @@
        i32.mul
        i32.sub
        local.set $minor|335
+       i32.const 0
+       i32.const 3
+       i32.ge_s
+       drop
        i32.const 1808
        local.get $minor|335
        i32.const 3