llvmpipe: Implement non SSE4.1 versions of floor and round.

3 files changed, 159 insertions, 35 deletions

diff --git a/src/gallium/drivers/llvmpipe/lp_bld_arit.c b/src/gallium/drivers/llvmpipe/lp_bld_arit.c
index e8c5fa3..f878706 100644
--- a/src/gallium/drivers/llvmpipe/lp_bld_arit.c
+++ b/src/gallium/drivers/llvmpipe/lp_bld_arit.c
@@ -675,6 +675,8 @@ lp_build_round_sse41(struct lp_build_context *bld,
 
    assert(type.floating);
    assert(type.width*type.length == 128);
+   assert(lp_check_value(type, a));
+   assert(util_cpu_caps.has_sse4_1);
 
    switch(type.width) {
    case 32:
@@ -694,19 +696,45 @@ lp_build_round_sse41(struct lp_build_context *bld,
 
 
 LLVMValueRef
+lp_build_trunc(struct lp_build_context *bld,
+               LLVMValueRef a)
+{
+   const struct lp_type type = bld->type;
+
+   assert(type.floating);
+   assert(lp_check_value(type, a));
+
+   if(util_cpu_caps.has_sse4_1)
+      return lp_build_round_sse41(bld, a, LP_BUILD_ROUND_SSE41_TRUNCATE);
+   else {
+      LLVMTypeRef vec_type = lp_build_vec_type(type);
+      LLVMTypeRef int_vec_type = lp_build_int_vec_type(type);
+      LLVMValueRef res;
+      res = LLVMBuildFPToSI(bld->builder, a, int_vec_type, "");
+      res = LLVMBuildSIToFP(bld->builder, res, vec_type, "");
+      return res;
+   }
+}
+
+
+LLVMValueRef
 lp_build_round(struct lp_build_context *bld,
                LLVMValueRef a)
 {
    const struct lp_type type = bld->type;
 
    assert(type.floating);
+   assert(lp_check_value(type, a));
 
    if(util_cpu_caps.has_sse4_1)
       return lp_build_round_sse41(bld, a, LP_BUILD_ROUND_SSE41_NEAREST);
-
-   /* FIXME */
-   assert(0);
-   return bld->undef;
+   else {
+      LLVMTypeRef vec_type = lp_build_vec_type(type);
+      LLVMValueRef res;
+      res = lp_build_iround(bld, a);
+      res = LLVMBuildSIToFP(bld->builder, res, vec_type, "");
+      return res;
+   }
 }
 
 
@@ -720,10 +748,13 @@ lp_build_floor(struct lp_build_context *bld,
 
    if(util_cpu_caps.has_sse4_1)
       return lp_build_round_sse41(bld, a, LP_BUILD_ROUND_SSE41_FLOOR);
-
-   /* FIXME */
-   assert(0);
-   return bld->undef;
+   else {
+      LLVMTypeRef vec_type = lp_build_vec_type(type);
+      LLVMValueRef res;
+      res = lp_build_ifloor(bld, a);
+      res = LLVMBuildSIToFP(bld->builder, res, vec_type, "");
+      return res;
+   }
 }
 
 
@@ -734,47 +765,74 @@ lp_build_ceil(struct lp_build_context *bld,
    const struct lp_type type = bld->type;
 
    assert(type.floating);
+   assert(lp_check_value(type, a));
 
    if(util_cpu_caps.has_sse4_1)
       return lp_build_round_sse41(bld, a, LP_BUILD_ROUND_SSE41_CEIL);
-
-   /* FIXME */
-   assert(0);
-   return bld->undef;
+   else {
+      LLVMTypeRef vec_type = lp_build_vec_type(type);
+      LLVMValueRef res;
+      res = lp_build_iceil(bld, a);
+      res = LLVMBuildSIToFP(bld->builder, res, vec_type, "");
+      return res;
+   }
 }
 
 
+/**
+ * Convert to integer, through whichever rounding method that's fastest,
+ * typically truncating to zero.
+ */
 LLVMValueRef
-lp_build_trunc(struct lp_build_context *bld,
-               LLVMValueRef a)
+lp_build_itrunc(struct lp_build_context *bld,
+                LLVMValueRef a)
 {
    const struct lp_type type = bld->type;
+   LLVMTypeRef int_vec_type = lp_build_int_vec_type(type);
 
    assert(type.floating);
+   assert(lp_check_value(type, a));
 
-   if(util_cpu_caps.has_sse4_1)
-      return lp_build_round_sse41(bld, a, LP_BUILD_ROUND_SSE41_TRUNCATE);
-
-   /* FIXME */
-   assert(0);
-   return bld->undef;
+   return LLVMBuildFPToSI(bld->builder, a, int_vec_type, "");
 }
 
 
-/**
- * Convert to integer, through whichever rounding method that's fastest,
- * typically truncating to zero.
- */
 LLVMValueRef
-lp_build_int(struct lp_build_context *bld,
-             LLVMValueRef a)
+lp_build_iround(struct lp_build_context *bld,
+                LLVMValueRef a)
 {
    const struct lp_type type = bld->type;
    LLVMTypeRef int_vec_type = lp_build_int_vec_type(type);
+   LLVMValueRef res;
 
    assert(type.floating);
+   assert(lp_check_value(type, a));
 
-   return LLVMBuildFPToSI(bld->builder, a, int_vec_type, "");
+   if(util_cpu_caps.has_sse4_1) {
+      res = lp_build_round_sse41(bld, a, LP_BUILD_ROUND_SSE41_NEAREST);
+   }
+   else {
+      LLVMTypeRef vec_type = lp_build_vec_type(type);
+      LLVMValueRef mask = lp_build_int_const_scalar(type, (unsigned long long)1 << (type.width - 1));
+      LLVMValueRef sign;
+      LLVMValueRef half;
+
+      /* get sign bit */
+      sign = LLVMBuildBitCast(bld->builder, a, int_vec_type, "");
+      sign = LLVMBuildAnd(bld->builder, sign, mask, "");
+
+      /* sign * 0.5 */
+      half = lp_build_const_scalar(type, 0.5);
+      half = LLVMBuildBitCast(bld->builder, half, int_vec_type, "");
+      half = LLVMBuildOr(bld->builder, sign, half, "");
+      half = LLVMBuildBitCast(bld->builder, half, vec_type, "");
+
+      res = LLVMBuildAdd(bld->builder, a, half, "");
+   }
+
+   res = LLVMBuildFPToSI(bld->builder, res, int_vec_type, "");
+
+   return res;
 }
 
 
@@ -782,9 +840,68 @@ LLVMValueRef
 lp_build_ifloor(struct lp_build_context *bld,
                 LLVMValueRef a)
 {
-   a = lp_build_floor(bld, a);
-   a = lp_build_int(bld, a);
-   return a;
+   const struct lp_type type = bld->type;
+   LLVMTypeRef int_vec_type = lp_build_int_vec_type(type);
+   LLVMValueRef res;
+
+   assert(type.floating);
+   assert(lp_check_value(type, a));
+
+   if(util_cpu_caps.has_sse4_1) {
+      res = lp_build_round_sse41(bld, a, LP_BUILD_ROUND_SSE41_FLOOR);
+   }
+   else {
+      /* Take the sign bit and add it to 1 constant */
+      LLVMTypeRef vec_type = lp_build_vec_type(type);
+      unsigned mantissa = lp_mantissa(type);
+      LLVMValueRef mask = lp_build_int_const_scalar(type, (unsigned long long)1 << (type.width - 1));
+      LLVMValueRef sign;
+      LLVMValueRef offset;
+
+      /* sign = a < 0 ? ~0 : 0 */
+      sign = LLVMBuildBitCast(bld->builder, a, int_vec_type, "");
+      sign = LLVMBuildAnd(bld->builder, sign, mask, "");
+      sign = LLVMBuildAShr(bld->builder, sign, lp_build_int_const_scalar(type, type.width - 1), "");
+
+      /* offset = -0.99999(9)f */
+      offset = lp_build_const_scalar(type, -(double)(((unsigned long long)1 << mantissa) - 1)/((unsigned long long)1 << mantissa));
+      offset = LLVMConstBitCast(offset, int_vec_type);
+
+      /* offset = a < 0 ? -0.99999(9)f : 0.0f */
+      offset = LLVMBuildAnd(bld->builder, offset, sign, "");
+      offset = LLVMBuildBitCast(bld->builder, offset, vec_type, "");
+
+      res = LLVMBuildAdd(bld->builder, a, offset, "");
+   }
+
+   res = LLVMBuildFPToSI(bld->builder, res, int_vec_type, "");
+
+   return res;
+}
+
+
+LLVMValueRef
+lp_build_iceil(struct lp_build_context *bld,
+               LLVMValueRef a)
+{
+   const struct lp_type type = bld->type;
+   LLVMTypeRef int_vec_type = lp_build_int_vec_type(type);
+   LLVMValueRef res;
+
+   assert(type.floating);
+   assert(lp_check_value(type, a));
+
+   if(util_cpu_caps.has_sse4_1) {
+      res = lp_build_round_sse41(bld, a, LP_BUILD_ROUND_SSE41_CEIL);
+   }
+   else {
+      assert(0);
+      res = bld->undef;
+   }
+
+   res = LLVMBuildFPToSI(bld->builder, res, int_vec_type, "");
+
+   return res;
 }
 
 
diff --git a/src/gallium/drivers/llvmpipe/lp_bld_arit.h b/src/gallium/drivers/llvmpipe/lp_bld_arit.h
index d68a97c..095a8e1 100644
--- a/src/gallium/drivers/llvmpipe/lp_bld_arit.h
+++ b/src/gallium/drivers/llvmpipe/lp_bld_arit.h
@@ -126,11 +126,18 @@ lp_build_trunc(struct lp_build_context *bld,
                LLVMValueRef a);
 
 LLVMValueRef
-lp_build_int(struct lp_build_context *bld,
-             LLVMValueRef a);
+lp_build_ifloor(struct lp_build_context *bld,
+                LLVMValueRef a);
+LLVMValueRef
+lp_build_iceil(struct lp_build_context *bld,
+               LLVMValueRef a);
 
 LLVMValueRef
-lp_build_ifloor(struct lp_build_context *bld,
+lp_build_iround(struct lp_build_context *bld,
+                LLVMValueRef a);
+
+LLVMValueRef
+lp_build_itrunc(struct lp_build_context *bld,
                 LLVMValueRef a);
 
 LLVMValueRef
diff --git a/src/gallium/drivers/llvmpipe/lp_bld_sample_soa.c b/src/gallium/drivers/llvmpipe/lp_bld_sample_soa.c
index 8ca1be6..1a47ca3 100644
--- a/src/gallium/drivers/llvmpipe/lp_bld_sample_soa.c
+++ b/src/gallium/drivers/llvmpipe/lp_bld_sample_soa.c
@@ -274,8 +274,8 @@ lp_build_sample_2d_linear_soa(struct lp_build_sample_context *bld,
    s_fpart = lp_build_sub(&bld->coord_bld, s, s_ipart);
    t_fpart = lp_build_sub(&bld->coord_bld, t, t_ipart);
 
-   x0 = lp_build_int(&bld->coord_bld, s_ipart);
-   y0 = lp_build_int(&bld->coord_bld, t_ipart);
+   x0 = lp_build_itrunc(&bld->coord_bld, s_ipart);
+   y0 = lp_build_itrunc(&bld->coord_bld, t_ipart);
 
    x0 = lp_build_sample_wrap(bld, x0, width,  bld->static_state->pot_width,  bld->static_state->wrap_s);
    y0 = lp_build_sample_wrap(bld, y0, height, bld->static_state->pot_height, bld->static_state->wrap_t);