From 8074a040e7a99a66cf7149d470f3a0f8eb6f3fd4 Mon Sep 17 00:00:00 2001
From: Italo Nicola <italonicola@collabora.com>
Date: Mon, 19 Apr 2021 09:43:30 +0000
Subject: [PATCH] util: add util_sign_extend

This code is taken from src/freedreno/isa/decode.c.
Since we need a similar function in panfrost, it's probably good to move
it to utils.

Signed-off-by: Italo Nicola <italonicola@collabora.com>
Acked-by: Rob Clark <robclark@freedesktop.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9461>
---
 src/freedreno/isa/decode.c | 17 +++--------------
 src/util/u_math.h          | 14 ++++++++++++++
 2 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/src/freedreno/isa/decode.c b/src/freedreno/isa/decode.c
index 57fafe00680..c8c8aa9874e 100644
--- a/src/freedreno/isa/decode.c
+++ b/src/freedreno/isa/decode.c
@@ -479,17 +479,6 @@ isa_decode_field(struct decode_scope *scope, const char *field_name)
 	return val;
 }
 
-static int64_t
-sign_extend(uint64_t val, unsigned width)
-{
-	assert(width > 0);
-	if (val & (UINT64_C(1) << (width - 1))) {
-		return -(int64_t)((UINT64_C(1) << width) - val);
-	} else {
-		return val;
-	}
-}
-
 static void
 display_field(struct decode_scope *scope, const char *field_name)
 {
@@ -528,7 +517,7 @@ display_field(struct decode_scope *scope, const char *field_name)
 	/* Basic types: */
 	case TYPE_BRANCH:
 		if (scope->state->options->branch_labels) {
-			int offset = sign_extend(val, width) + scope->state->n;
+			int offset = util_sign_extend(val, width) + scope->state->n;
 			if (offset < scope->state->num_instr) {
 				fprintf(out, "l%d", offset);
 				BITSET_SET(scope->state->branch_targets, offset);
@@ -537,7 +526,7 @@ display_field(struct decode_scope *scope, const char *field_name)
 		}
 		FALLTHROUGH;
 	case TYPE_INT:
-		fprintf(out, "%"PRId64, sign_extend(val, width));
+		fprintf(out, "%"PRId64, util_sign_extend(val, width));
 		break;
 	case TYPE_UINT:
 		fprintf(out, "%"PRIu64, val);
@@ -548,7 +537,7 @@ display_field(struct decode_scope *scope, const char *field_name)
 		break;
 	case TYPE_OFFSET:
 		if (val != 0) {
-			fprintf(out, "%+"PRId64, sign_extend(val, width));
+			fprintf(out, "%+"PRId64, util_sign_extend(val, width));
 		}
 		break;
 	case TYPE_FLOAT:
diff --git a/src/util/u_math.h b/src/util/u_math.h
index 2b12267b961..567c51d7aec 100644
--- a/src/util/u_math.h
+++ b/src/util/u_math.h
@@ -642,6 +642,20 @@ util_bswap16(uint16_t n)
           (n << 8);
 }
 
+/**
+ * Extend sign.
+ */
+static inline int64_t
+util_sign_extend(uint64_t val, unsigned width)
+{
+	assert(width > 0);
+	if (val & (UINT64_C(1) << (width - 1))) {
+		return -(int64_t)((UINT64_C(1) << width) - val);
+	} else {
+		return val;
+	}
+}
+
 static inline void*
 util_memcpy_cpu_to_le32(void * restrict dest, const void * restrict src, size_t n)
 {