gallivm: fix [IU]MUL_HI regression

This patch does two things:

1. It separates the host-CPU code generation from the generic code
   generation. This guards against accidently breaking things for
   radeonsi in the future.

2. It makes sure we actually use both arguments and don't just compute
   a square :-p

Fixes a regression introduced by commit 29279f44b3172ef3b84d470e70fc7684695ced4b

Cc: Roland Scheidegger <[email protected]>
Reviewed-by: Roland Scheidegger <[email protected]>

3 files changed, 90 insertions, 28 deletions

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_arit.c b/src/gallium/auxiliary/gallivm/lp_bld_arit.c
index 3de46287f70..43ad238393c 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_arit.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_arit.c
@@ -1094,12 +1094,14 @@ lp_build_mul(struct lp_build_context *bld,
 /*
  * Widening mul, valid for 32x32 bit -> 64bit only.
  * Result is low 32bits, high bits returned in res_hi.
+ *
+ * Emits code that is meant to be compiled for the host CPU.
  */
 LLVMValueRef
-lp_build_mul_32_lohi(struct lp_build_context *bld,
-                     LLVMValueRef a,
-                     LLVMValueRef b,
-                     LLVMValueRef *res_hi)
+lp_build_mul_32_lohi_cpu(struct lp_build_context *bld,
+                         LLVMValueRef a,
+                         LLVMValueRef b,
+                         LLVMValueRef *res_hi)
 {
    struct gallivm_state *gallivm = bld->gallivm;
    LLVMBuilderRef builder = gallivm->builder;
@@ -1216,29 +1218,47 @@ lp_build_mul_32_lohi(struct lp_build_context *bld,
       return LLVMBuildShuffleVector(builder, muleven, mulodd, shuf_vec, "");
    }
    else {
-      LLVMValueRef tmp;
-      struct lp_type type_tmp;
-      LLVMTypeRef wide_type, cast_type;
-
-      type_tmp = bld->type;
-      type_tmp.width *= 2;
-      wide_type = lp_build_vec_type(gallivm, type_tmp);
-      type_tmp = bld->type;
-      type_tmp.length *= 2;
-      cast_type = lp_build_vec_type(gallivm, type_tmp);
-
-      if (bld->type.sign) {
-         a = LLVMBuildSExt(builder, a, wide_type, "");
-         b = LLVMBuildSExt(builder, b, wide_type, "");
-      } else {
-         a = LLVMBuildZExt(builder, a, wide_type, "");
-         b = LLVMBuildZExt(builder, b, wide_type, "");
-      }
-      tmp = LLVMBuildMul(builder, a, b, "");
-      tmp = LLVMBuildBitCast(builder, tmp, cast_type, "");
-      *res_hi = lp_build_uninterleave1(gallivm, bld->type.length * 2, tmp, 1);
-      return lp_build_uninterleave1(gallivm, bld->type.length * 2, tmp, 0);
+      return lp_build_mul_32_lohi(bld, a, b, res_hi);
+   }
+}
+
+
+/*
+ * Widening mul, valid for 32x32 bit -> 64bit only.
+ * Result is low 32bits, high bits returned in res_hi.
+ *
+ * Emits generic code.
+ */
+LLVMValueRef
+lp_build_mul_32_lohi(struct lp_build_context *bld,
+                     LLVMValueRef a,
+                     LLVMValueRef b,
+                     LLVMValueRef *res_hi)
+{
+   struct gallivm_state *gallivm = bld->gallivm;
+   LLVMBuilderRef builder = gallivm->builder;
+   LLVMValueRef tmp;
+   struct lp_type type_tmp;
+   LLVMTypeRef wide_type, cast_type;
+
+   type_tmp = bld->type;
+   type_tmp.width *= 2;
+   wide_type = lp_build_vec_type(gallivm, type_tmp);
+   type_tmp = bld->type;
+   type_tmp.length *= 2;
+   cast_type = lp_build_vec_type(gallivm, type_tmp);
+
+   if (bld->type.sign) {
+      a = LLVMBuildSExt(builder, a, wide_type, "");
+      b = LLVMBuildSExt(builder, b, wide_type, "");
+   } else {
+      a = LLVMBuildZExt(builder, a, wide_type, "");
+      b = LLVMBuildZExt(builder, b, wide_type, "");
    }
+   tmp = LLVMBuildMul(builder, a, b, "");
+   tmp = LLVMBuildBitCast(builder, tmp, cast_type, "");
+   *res_hi = lp_build_uninterleave1(gallivm, bld->type.length * 2, tmp, 1);
+   return lp_build_uninterleave1(gallivm, bld->type.length * 2, tmp, 0);
 }
 
 
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_arit.h b/src/gallium/auxiliary/gallivm/lp_bld_arit.h
index 5d48b1c837d..2a4137a6780 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_arit.h
+++ b/src/gallium/auxiliary/gallivm/lp_bld_arit.h
@@ -77,6 +77,12 @@ lp_build_mul(struct lp_build_context *bld,
              LLVMValueRef b);
 
 LLVMValueRef
+lp_build_mul_32_lohi_cpu(struct lp_build_context *bld,
+                         LLVMValueRef a,
+                         LLVMValueRef b,
+                         LLVMValueRef *res_hi);
+
+LLVMValueRef
 lp_build_mul_32_lohi(struct lp_build_context *bld,
                      LLVMValueRef a,
                      LLVMValueRef b,
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_tgsi_action.c b/src/gallium/auxiliary/gallivm/lp_bld_tgsi_action.c
index 72d4579a042..9c6fc4b4ae6 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_tgsi_action.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_tgsi_action.c
@@ -849,7 +849,24 @@ imul_hi_emit(
 
    /* low result bits are tossed away */
    lp_build_mul_32_lohi(int_bld, emit_data->args[0],
-                        emit_data->args[0], &hi_bits);
+                        emit_data->args[1], &hi_bits);
+   emit_data->output[emit_data->chan] = hi_bits;
+}
+
+static void
+imul_hi_emit_cpu(
+   const struct lp_build_tgsi_action * action,
+   struct lp_build_tgsi_context * bld_base,
+   struct lp_build_emit_data * emit_data)
+{
+   struct lp_build_context *int_bld = &bld_base->int_bld;
+   LLVMValueRef hi_bits;
+
+   assert(int_bld->type.width == 32);
+
+   /* low result bits are tossed away */
+   lp_build_mul_32_lohi_cpu(int_bld, emit_data->args[0],
+                            emit_data->args[1], &hi_bits);
    emit_data->output[emit_data->chan] = hi_bits;
 }
 
@@ -867,7 +884,24 @@ umul_hi_emit(
 
    /* low result bits are tossed away */
    lp_build_mul_32_lohi(uint_bld, emit_data->args[0],
-                        emit_data->args[0], &hi_bits);
+                        emit_data->args[1], &hi_bits);
+   emit_data->output[emit_data->chan] = hi_bits;
+}
+
+static void
+umul_hi_emit_cpu(
+   const struct lp_build_tgsi_action * action,
+   struct lp_build_tgsi_context * bld_base,
+   struct lp_build_emit_data * emit_data)
+{
+   struct lp_build_context *uint_bld = &bld_base->uint_bld;
+   LLVMValueRef hi_bits;
+
+   assert(uint_bld->type.width == 32);
+
+   /* low result bits are tossed away */
+   lp_build_mul_32_lohi_cpu(uint_bld, emit_data->args[0],
+                            emit_data->args[1], &hi_bits);
    emit_data->output[emit_data->chan] = hi_bits;
 }
 
@@ -2581,6 +2615,8 @@ lp_set_default_actions_cpu(
    bld_base->op_actions[TGSI_OPCODE_ISHR].emit = ishr_emit_cpu;
    bld_base->op_actions[TGSI_OPCODE_ISLT].emit = islt_emit_cpu;
    bld_base->op_actions[TGSI_OPCODE_ISSG].emit = issg_emit_cpu;
+   bld_base->op_actions[TGSI_OPCODE_IMUL_HI].emit = imul_hi_emit_cpu;
+   bld_base->op_actions[TGSI_OPCODE_UMUL_HI].emit = umul_hi_emit_cpu;
 
    bld_base->op_actions[TGSI_OPCODE_LG2].emit = lg2_emit_cpu;
    bld_base->op_actions[TGSI_OPCODE_LOG].emit = log_emit_cpu;