Author: Matt Arsenault
Date: 2026-03-12T11:47:39+01:00
New Revision: 3c7f70bb9cee9bbe7b098c1b56da3a79110ffcb8

URL: 
https://github.com/llvm/llvm-project/commit/3c7f70bb9cee9bbe7b098c1b56da3a79110ffcb8
DIFF: 
https://github.com/llvm/llvm-project/commit/3c7f70bb9cee9bbe7b098c1b56da3a79110ffcb8.diff

LOG: libclc: Replace fmod implementation with elementwise builtin (#186083)

This corresponds to frem, which for whatever reason is a first
class IR instruction. The backend has a heroic freestanding
implementation that should be nearly identical to what was here.

Added: 
    

Modified: 
    libclc/clc/lib/generic/math/clc_fmod.cl

Removed: 
    


################################################################################
diff  --git a/libclc/clc/lib/generic/math/clc_fmod.cl 
b/libclc/clc/lib/generic/math/clc_fmod.cl
index 7f60b403b53e6..629c610748618 100644
--- a/libclc/clc/lib/generic/math/clc_fmod.cl
+++ b/libclc/clc/lib/generic/math/clc_fmod.cl
@@ -6,187 +6,10 @@
 //
 
//===----------------------------------------------------------------------===//
 
-#include <clc/clc_convert.h>
-#include <clc/integer/clc_clz.h>
 #include <clc/internal/clc.h>
-#include <clc/math/clc_floor.h>
-#include <clc/math/clc_fma.h>
-#include <clc/math/clc_ldexp.h>
-#include <clc/math/clc_trunc.h>
-#include <clc/math/math.h>
-#include <clc/shared/clc_max.h>
 
-_CLC_DEF _CLC_OVERLOAD float __clc_fmod(float x, float y) {
-  int ux = __clc_as_int(x);
-  int ax = ux & EXSIGNBIT_SP32;
-  float xa = __clc_as_float(ax);
-  int sx = ux ^ ax;
-  int ex = ax >> EXPSHIFTBITS_SP32;
-
-  int uy = __clc_as_int(y);
-  int ay = uy & EXSIGNBIT_SP32;
-  float ya = __clc_as_float(ay);
-  int ey = ay >> EXPSHIFTBITS_SP32;
-
-  float xr = __clc_as_float(0x3f800000 | (ax & 0x007fffff));
-  float yr = __clc_as_float(0x3f800000 | (ay & 0x007fffff));
-  int c;
-  int k = ex - ey;
-
-  while (k > 0) {
-    c = xr >= yr;
-    xr -= c ? yr : 0.0f;
-    xr += xr;
-    --k;
-  }
-
-  c = xr >= yr;
-  xr -= c ? yr : 0.0f;
-
-  int lt = ex < ey;
-
-  xr = lt ? xa : xr;
-  yr = lt ? ya : yr;
-
-  float s = __clc_as_float(ey << EXPSHIFTBITS_SP32);
-  xr *= lt ? 1.0f : s;
-
-  c = ax == ay;
-  xr = c ? 0.0f : xr;
-
-  xr = __clc_as_float(sx ^ __clc_as_int(xr));
-
-  c = ax > PINFBITPATT_SP32 | ay > PINFBITPATT_SP32 | ax == PINFBITPATT_SP32 |
-      ay == 0;
-  xr = c ? __clc_as_float(QNANBITPATT_SP32) : xr;
-
-  return xr;
-}
-
-#define __CLC_FLOAT_ONLY
 #define __CLC_FUNCTION __clc_fmod
-#define __CLC_BODY <clc/shared/binary_def_scalarize.inc>
-#include <clc/math/gentype.inc>
-#undef __CLC_FUNCTION
-
-#ifdef cl_khr_fp64
-
-#pragma OPENCL EXTENSION cl_khr_fp64 : enable
-
-_CLC_DEF _CLC_OVERLOAD double __clc_fmod(double x, double y) {
-  ulong ux = __clc_as_ulong(x);
-  ulong ax = ux & ~SIGNBIT_DP64;
-  ulong xsgn = ux ^ ax;
-  double dx = __clc_as_double(ax);
-  int xexp = __clc_convert_int(ax >> EXPSHIFTBITS_DP64);
-  int xexp1 = 11 - (int)__clc_clz(ax & MANTBITS_DP64);
-  xexp1 = xexp < 1 ? xexp1 : xexp;
-
-  ulong uy = __clc_as_ulong(y);
-  ulong ay = uy & ~SIGNBIT_DP64;
-  double dy = __clc_as_double(ay);
-  int yexp = __clc_convert_int(ay >> EXPSHIFTBITS_DP64);
-  int yexp1 = 11 - (int)__clc_clz(ay & MANTBITS_DP64);
-  yexp1 = yexp < 1 ? yexp1 : yexp;
-
-  // First assume |x| > |y|
-
-  // Set ntimes to the number of times we need to do a
-  // partial remainder. If the exponent of x is an exact multiple
-  // of 53 larger than the exponent of y, and the mantissa of x is
-  // less than the mantissa of y, ntimes will be one too large
-  // but it doesn't matter - it just means that we'll go round
-  // the loop below one extra time.
-  int ntimes = __clc_max(0, (xexp1 - yexp1) / 53);
-  double w = __clc_ldexp(dy, ntimes * 53);
-  w = ntimes == 0 ? dy : w;
-  double scale = ntimes == 0 ? 1.0 : 0x1.0p-53;
-
-  // Each time round the loop we compute a partial remainder.
-  // This is done by subtracting a large multiple of w
-  // from x each time, where w is a scaled up version of y.
-  // The subtraction must be performed exactly in quad
-  // precision, though the result at each stage can
-  // fit exactly in a double precision number.
-  int i;
-  double t, v, p, pp;
-
-  for (i = 0; i < ntimes; i++) {
-    // Compute integral multiplier
-    t = __clc_trunc(dx / w);
-
-    // Compute w * t in quad precision
-    p = w * t;
-    pp = __clc_fma(w, t, -p);
+#define __CLC_IMPL_FUNCTION(x) __builtin_elementwise_fmod
+#define __CLC_BODY <clc/shared/binary_def.inc>
 
-    // Subtract w * t from dx
-    v = dx - p;
-    dx = v + (((dx - v) - p) - pp);
-
-    // If t was one too large, dx will be negative. Add back one w.
-    dx += dx < 0.0 ? w : 0.0;
-
-    // Scale w down by 2^(-53) for the next iteration
-    w *= scale;
-  }
-
-  // One more time
-  t = __clc_floor(dx / w);
-
-  p = w * t;
-  pp = __clc_fma(w, t, -p);
-  v = dx - p;
-  dx = v + (((dx - v) - p) - pp);
-  i = dx < 0.0;
-  dx += i ? w : 0.0;
-
-  // At this point, dx lies in the range [0,dy)
-  double ret = __clc_as_double(xsgn ^ __clc_as_ulong(dx));
-  dx = __clc_as_double(ax);
-
-  // Now handle |x| == |y|
-  int c = dx == dy;
-  t = __clc_as_double(xsgn);
-  ret = c ? t : ret;
-
-  // Next, handle |x| < |y|
-  c = dx < dy;
-  ret = c ? x : ret;
-
-  // We don't need anything special for |x| == 0
-
-  // |y| is 0
-  c = dy == 0.0;
-  ret = c ? __clc_as_double(QNANBITPATT_DP64) : ret;
-
-  // y is +-Inf, NaN
-  c = yexp > BIASEDEMAX_DP64;
-  t = y == y ? x : y;
-  ret = c ? t : ret;
-
-  // x is +=Inf, NaN
-  c = xexp > BIASEDEMAX_DP64;
-  ret = c ? __clc_as_double(QNANBITPATT_DP64) : ret;
-
-  return ret;
-}
-
-#define __CLC_DOUBLE_ONLY
-#define __CLC_FUNCTION __clc_fmod
-#define __CLC_BODY <clc/shared/binary_def_scalarize.inc>
-#include <clc/math/gentype.inc>
-#undef __CLC_FUNCTION
-
-#endif
-
-#ifdef cl_khr_fp16
-
-#pragma OPENCL EXTENSION cl_khr_fp16 : enable
-
-// Forward the half version of this builtin onto the float one
-#define __CLC_HALF_ONLY
-#define __CLC_FUNCTION __clc_fmod
-#define __CLC_BODY <clc/math/binary_def_via_fp32.inc>
 #include <clc/math/gentype.inc>
-
-#endif


        
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