workaround {.noInit.} mangling in templates

mratsim · Jan 20, 2024 · 887e3c8 · 887e3c8
1 parent 173900f
commit 887e3c8
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Showing 2 changed files with 8 additions and 4 deletions.
diff --git a/constantine/math/elliptic/ec_endomorphism_accel.nim b/constantine/math/elliptic/ec_endomorphism_accel.nim
@@ -47,13 +47,17 @@ template decomposeEndoImpl[scalBits: static int](
   static: doAssert L >= ceilDiv_vartime(scalBits, M) + 1
   const w = F.C.getCurveOrderBitwidth().wordsRequired()
 
+  # Upstream bug:
+  #   {.noInit.} variables must be {.inject.} as well
+  #   or they'll be mangled as foo`gensym12345 instead of fooX60gensym12345 in C codegen
+
   when M == 2:
-    var alphas{.noInit.}: (
+    var alphas{.noInit, inject.}: (
       BigInt[scalBits + babai(F)[0][0].bits],
       BigInt[scalBits + babai(F)[1][0].bits]
     )
   elif M == 4:
-    var alphas{.noInit.}: (
+    var alphas{.noInit, inject.}: (
       BigInt[scalBits + babai(F)[0][0].bits],
       BigInt[scalBits + babai(F)[1][0].bits],
       BigInt[scalBits + babai(F)[2][0].bits],
@@ -72,7 +76,7 @@ template decomposeEndoImpl[scalBits: static int](
   # and     kj = 0 - 𝛼j b0j - 𝛼1 b1j ... - 𝛼m bmj
   var
     k {.inject.}: array[M, BigInt[scalBits]] # zero-init required
-    alphaB {.noInit.}: BigInt[scalBits]
+    alphaB {.noInit, inject.}: BigInt[scalBits]
   k[0] = scalar
   staticFor miniScalarIdx, 0, M:
     staticFor basisIdx, 0, M:

diff --git a/constantine/math/elliptic/ec_multi_scalar_mul_parallel.nim b/constantine/math/elliptic/ec_multi_scalar_mul_parallel.nim
@@ -329,7 +329,7 @@ proc msmAffine_vartime_parallel[bits: static int, EC, ECaff](
 
   # Prologue
   # --------
-  const numBuckets = 1 shl (c-1)
+  const numBuckets {.used.} = 1 shl (c-1)
   const numFullWindows = bits div c
   const numWindows = numFullWindows + 1 # Even if `bits div c` is exact, the signed recoding needs to see an extra 0 after the MSB