Mesa (master): ac/llvm: add AC_FLOAT_MODE_ROUND_TO_ZERO

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Module: Mesa
Branch: master
Commit: 7dfb15fff1d765689353419c0a0ac9c96786b021
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=7dfb15fff1d765689353419c0a0ac9c96786b021

Author: Samuel Pitoiset <samuel.pitoiset at gmail.com>
Date:   Mon Oct 14 15:36:37 2019 +0200

ac/llvm: add AC_FLOAT_MODE_ROUND_TO_ZERO

Because some instructions will be optimized by the backend compiler,
the driver has to manually flush to zero to keep the result exact.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>

---

 src/amd/llvm/ac_llvm_build.c    | 1 +
 src/amd/llvm/ac_llvm_build.h    | 2 ++
 src/amd/llvm/ac_llvm_helper.cpp | 1 +
 src/amd/llvm/ac_llvm_util.h     | 1 +
 4 files changed, 5 insertions(+)

diff --git a/src/amd/llvm/ac_llvm_build.c b/src/amd/llvm/ac_llvm_build.c
index 87adf2b4432..d9ece7049c7 100644
--- a/src/amd/llvm/ac_llvm_build.c
+++ b/src/amd/llvm/ac_llvm_build.c
@@ -73,6 +73,7 @@ ac_llvm_context_init(struct ac_llvm_context *ctx,
 	ctx->family = family;
 	ctx->wave_size = wave_size;
 	ctx->ballot_mask_bits = ballot_mask_bits;
+	ctx->float_mode = float_mode;
 	ctx->module = ac_create_module(wave_size == 32 ? compiler->tm_wave32
 						       : compiler->tm,
 				       ctx->context);
diff --git a/src/amd/llvm/ac_llvm_build.h b/src/amd/llvm/ac_llvm_build.h
index a67e1d49d4d..8cd15cbe99f 100644
--- a/src/amd/llvm/ac_llvm_build.h
+++ b/src/amd/llvm/ac_llvm_build.h
@@ -120,6 +120,8 @@ struct ac_llvm_context {
 	unsigned wave_size;
 	unsigned ballot_mask_bits;
 
+	unsigned float_mode;
+
 	LLVMValueRef lds;
 };
 
diff --git a/src/amd/llvm/ac_llvm_helper.cpp b/src/amd/llvm/ac_llvm_helper.cpp
index b7a72ee3fdd..7f3ff71fd9c 100644
--- a/src/amd/llvm/ac_llvm_helper.cpp
+++ b/src/amd/llvm/ac_llvm_helper.cpp
@@ -82,6 +82,7 @@ LLVMBuilderRef ac_create_builder(LLVMContextRef ctx,
 
 	switch (float_mode) {
 	case AC_FLOAT_MODE_DEFAULT:
+	case AC_FLOAT_MODE_DENORM_FLUSH_TO_ZERO:
 		break;
 	case AC_FLOAT_MODE_NO_SIGNED_ZEROS_FP_MATH:
 		flags.setNoSignedZeros();
diff --git a/src/amd/llvm/ac_llvm_util.h b/src/amd/llvm/ac_llvm_util.h
index 60c9a17e447..a864f524fbe 100644
--- a/src/amd/llvm/ac_llvm_util.h
+++ b/src/amd/llvm/ac_llvm_util.h
@@ -73,6 +73,7 @@ enum ac_float_mode {
 	AC_FLOAT_MODE_DEFAULT,
 	AC_FLOAT_MODE_NO_SIGNED_ZEROS_FP_MATH,
 	AC_FLOAT_MODE_UNSAFE_FP_MATH,
+	AC_FLOAT_MODE_DENORM_FLUSH_TO_ZERO,
 };
 
 /* Per-thread persistent LLVM objects. */