Mesa (master): amd/common: lower bitfield_extract to ubfe/ibfe.

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Module: Mesa
Branch: master
Commit: 0daeb1d127987c8e70afe22cb30f676fb4631813
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=0daeb1d127987c8e70afe22cb30f676fb4631813

Author: Daniel Schürmann <daniel.schuermann at campus.tu-berlin.de>
Date:   Fri Jan 25 16:24:55 2019 +0100

amd/common: lower bitfield_extract to ubfe/ibfe.

Reviewed-by: Connor Abbott <cwabbott0 at gmail.com>

---

 src/amd/common/ac_llvm_build.c        | 21 ++++++++++++++++-----
 src/amd/common/ac_nir_to_llvm.c       | 34 ++++------------------------------
 src/amd/vulkan/radv_shader.c          |  1 +
 src/gallium/drivers/radeonsi/si_get.c |  1 +
 4 files changed, 22 insertions(+), 35 deletions(-)

diff --git a/src/amd/common/ac_llvm_build.c b/src/amd/common/ac_llvm_build.c
index 1e6247ad72e..edadd56cc7b 100644
--- a/src/amd/common/ac_llvm_build.c
+++ b/src/amd/common/ac_llvm_build.c
@@ -2798,11 +2798,22 @@ LLVMValueRef ac_build_bfe(struct ac_llvm_context *ctx, LLVMValueRef input,
 		width,
 	};
 
-	return ac_build_intrinsic(ctx,
-				  is_signed ? "llvm.amdgcn.sbfe.i32" :
-					      "llvm.amdgcn.ubfe.i32",
-				  ctx->i32, args, 3,
-				  AC_FUNC_ATTR_READNONE);
+	LLVMValueRef result = ac_build_intrinsic(ctx,
+						 is_signed ? "llvm.amdgcn.sbfe.i32" :
+							     "llvm.amdgcn.ubfe.i32",
+						 ctx->i32, args, 3,
+						 AC_FUNC_ATTR_READNONE);
+
+	if (HAVE_LLVM < 0x0800) {
+		/* FIXME: LLVM 7+ returns incorrect result when count is 0.
+		 * https://bugs.freedesktop.org/show_bug.cgi?id=107276
+		 */
+		LLVMValueRef zero = ctx->i32_0;
+		LLVMValueRef icond = LLVMBuildICmp(ctx->builder, LLVMIntEQ, width, zero, "");
+		result = LLVMBuildSelect(ctx->builder, icond, zero, result, "");
+	}
+
+	return result;
 }
 
 LLVMValueRef ac_build_imad(struct ac_llvm_context *ctx, LLVMValueRef s0,
diff --git a/src/amd/common/ac_nir_to_llvm.c b/src/amd/common/ac_nir_to_llvm.c
index 9b6e65db8b9..636fd4035c8 100644
--- a/src/amd/common/ac_nir_to_llvm.c
+++ b/src/amd/common/ac_nir_to_llvm.c
@@ -429,32 +429,6 @@ static LLVMValueRef emit_imul_high(struct ac_llvm_context *ctx,
 	return result;
 }
 
-static LLVMValueRef emit_bitfield_extract(struct ac_llvm_context *ctx,
-					  bool is_signed,
-					  const LLVMValueRef srcs[3])
-{
-	LLVMValueRef result;
-
-	if (HAVE_LLVM >= 0x0800) {
-		LLVMValueRef icond = LLVMBuildICmp(ctx->builder, LLVMIntEQ, srcs[2], LLVMConstInt(ctx->i32, 32, false), "");
-		result = ac_build_bfe(ctx, srcs[0], srcs[1], srcs[2], is_signed);
-		result = LLVMBuildSelect(ctx->builder, icond, srcs[0], result, "");
-	} else {
-		/* FIXME: LLVM 7+ returns incorrect result when count is 0.
-		 * https://bugs.freedesktop.org/show_bug.cgi?id=107276
-		 */
-		LLVMValueRef zero = ctx->i32_0;
-		LLVMValueRef icond1 = LLVMBuildICmp(ctx->builder, LLVMIntEQ, srcs[2], LLVMConstInt(ctx->i32, 32, false), "");
-		LLVMValueRef icond2 = LLVMBuildICmp(ctx->builder, LLVMIntEQ, srcs[2], zero, "");
-
-		result = ac_build_bfe(ctx, srcs[0], srcs[1], srcs[2], is_signed);
-		result = LLVMBuildSelect(ctx->builder, icond1, srcs[0], result, "");
-		result = LLVMBuildSelect(ctx->builder, icond2, zero, result, "");
-	}
-
-	return result;
-}
-
 static LLVMValueRef emit_bfm(struct ac_llvm_context *ctx,
 			     LLVMValueRef bits, LLVMValueRef offset)
 {
@@ -837,11 +811,11 @@ static void visit_alu(struct ac_nir_context *ctx, const nir_alu_instr *instr)
 	case nir_op_bitfield_select:
 		result = emit_bitfield_select(&ctx->ac, src[0], src[1], src[2]);
 		break;
-	case nir_op_ibitfield_extract:
-		result = emit_bitfield_extract(&ctx->ac, true, src);
+	case nir_op_ubfe:
+		result = ac_build_bfe(&ctx->ac, src[0], src[1], src[2], false);
 		break;
-	case nir_op_ubitfield_extract:
-		result = emit_bitfield_extract(&ctx->ac, false, src);
+	case nir_op_ibfe:
+		result = ac_build_bfe(&ctx->ac, src[0], src[1], src[2], true);
 		break;
 	case nir_op_bitfield_reverse:
 		result = ac_build_bitfield_reverse(&ctx->ac, src[0]);
diff --git a/src/amd/vulkan/radv_shader.c b/src/amd/vulkan/radv_shader.c
index 3452a0b2ad2..c8dc9daf1bc 100644
--- a/src/amd/vulkan/radv_shader.c
+++ b/src/amd/vulkan/radv_shader.c
@@ -59,6 +59,7 @@ static const struct nir_shader_compiler_options nir_options = {
 	.lower_fsat = true,
 	.lower_fdiv = true,
 	.lower_bitfield_insert_to_bitfield_select = true,
+	.lower_bitfield_extract = true,
 	.lower_sub = true,
 	.lower_pack_snorm_2x16 = true,
 	.lower_pack_snorm_4x8 = true,
diff --git a/src/gallium/drivers/radeonsi/si_get.c b/src/gallium/drivers/radeonsi/si_get.c
index b7c7f1aa78c..5c2806341b3 100644
--- a/src/gallium/drivers/radeonsi/si_get.c
+++ b/src/gallium/drivers/radeonsi/si_get.c
@@ -488,6 +488,7 @@ static const struct nir_shader_compiler_options nir_options = {
 	.lower_fsat = true,
 	.lower_fdiv = true,
 	.lower_bitfield_insert_to_bitfield_select = true,
+	.lower_bitfield_extract = true,
 	.lower_sub = true,
 	.lower_ffma = true,
 	.lower_fmod = true,