diff --git a/llvm_util/llvm2alive.cpp b/llvm_util/llvm2alive.cpp
index 549a2e73a..6e6ef42b1 100644
--- a/llvm_util/llvm2alive.cpp
+++ b/llvm_util/llvm2alive.cpp
@@ -1739,24 +1739,26 @@ class llvm2alive_ : public llvm::InstVisitor<llvm2alive_, unique_ptr<Instr>> {
     }
   }
 
-  static FPDenormalAttrs::Type parse_fp_denormal_str(string_view str) {
-    if (str == "dynamic")       return FPDenormalAttrs::Dynamic;
-    if (str == "ieee")          return FPDenormalAttrs::IEEE;
-    if (str == "preserve-sign") return FPDenormalAttrs::PreserveSign;
-    if (str == "positive-zero") return FPDenormalAttrs::PositiveZero;
-    UNREACHABLE();
+  static FPDenormalAttrs::Type parse_fp_denormal(llvm::DenormalMode::DenormalModeKind mode) {
+    switch (mode) {
+    case llvm::DenormalMode::IEEE:
+      return FPDenormalAttrs::IEEE;
+    case llvm::DenormalMode::PositiveZero:
+      return FPDenormalAttrs::PositiveZero;
+    case llvm::DenormalMode::PreserveSign:
+      return FPDenormalAttrs::PreserveSign;
+    case llvm::DenormalMode::Dynamic:
+      return FPDenormalAttrs::Dynamic;
+    default:
+      UNREACHABLE();
+    }
   }
 
-  static FPDenormalAttrs parse_fp_denormal(string_view str) {
-    FPDenormalAttrs attr;
-    auto comma = str.find(',');
-    if (comma == string_view::npos) {
-      attr.input = attr.output = parse_fp_denormal_str(str);
-    } else {
-      attr.output = parse_fp_denormal_str(string_view(str.data(), comma));
-      attr.input  = parse_fp_denormal_str(str.data() + comma + 1);
-    }
-    return attr;
+  static FPDenormalAttrs parse_fp_denormal(llvm::DenormalMode mode) {
+    return {
+      .input = parse_fp_denormal(mode.Input),
+      .output = parse_fp_denormal(mode.Output),
+    };
   }
 
   static void handleFnAttrs(const llvm::AttributeSet &aset, FnAttrs &attrs) {
@@ -1764,11 +1766,7 @@ class llvm2alive_ : public llvm::InstVisitor<llvm2alive_, unique_ptr<Instr>> {
       if (llvmattr.isStringAttribute()) {
         auto str = llvmattr.getKindAsString();
         auto val = llvmattr.getValueAsString();
-        if (str == "denormal-fp-math") {
-          attrs.setFPDenormal(parse_fp_denormal(val));
-        } else if (str == "denormal-fp-math-f32") {
-          attrs.setFPDenormal(parse_fp_denormal(val), 32);
-        } else if (str == "alloc-family") {
+        if (str == "alloc-family") {
           attrs.allocfamily = val;
         }
       }
@@ -1790,6 +1788,13 @@ class llvm2alive_ : public llvm::InstVisitor<llvm2alive_, unique_ptr<Instr>> {
           attrs.allocsize_1 = *args.second;
         break;
       }
+      case llvm::Attribute::DenormalFPEnv: {
+        auto fp_env = llvmattr.getDenormalFPEnv();
+        attrs.setFPDenormal(parse_fp_denormal(fp_env.DefaultMode));
+        if (fp_env.F32Mode != fp_env.DefaultMode)
+          attrs.setFPDenormal(parse_fp_denormal(fp_env.F32Mode), 32);
+        break;
+      }
       case llvm::Attribute::AllocKind: {
         auto kind = llvmattr.getAllocKind();
         if ((kind & llvm::AllocFnKind::Alloc) != llvm::AllocFnKind::Unknown)
diff --git a/tests/alive-tv/fp/denormal-attrs-mismatch.srctgt.ll b/tests/alive-tv/fp/denormal-attrs-mismatch.srctgt.ll
new file mode 100644
index 000000000..34e1a9ec5
--- /dev/null
+++ b/tests/alive-tv/fp/denormal-attrs-mismatch.srctgt.ll
@@ -0,0 +1,9 @@
+; ERROR: Function attributes not refined
+
+define float @src(float %x) denormal_fpenv(positivezero) {
+  ret float %x
+}
+
+define float @tgt(float %x) {
+  ret float %x
+}
diff --git a/tests/alive-tv/fp/denormal-ieee-default.srctgt.ll b/tests/alive-tv/fp/denormal-ieee-default.srctgt.ll
new file mode 100644
index 000000000..1bf247737
--- /dev/null
+++ b/tests/alive-tv/fp/denormal-ieee-default.srctgt.ll
@@ -0,0 +1,9 @@
+; this transformation is OK since ieee is the default
+
+define float @src(float %x) denormal_fpenv(ieee) {
+  ret float %x
+}
+
+define float @tgt(float %x) {
+  ret float %x
+}
diff --git a/tests/alive-tv/fp/fadd-denormal.srctgt.ll b/tests/alive-tv/fp/fadd-denormal.srctgt.ll
index acc6f4a0a..cca8137ed 100644
--- a/tests/alive-tv/fp/fadd-denormal.srctgt.ll
+++ b/tests/alive-tv/fp/fadd-denormal.srctgt.ll
@@ -1,8 +1,8 @@
-define double @src() "denormal-fp-math"="positive-zero" {
+define double @src() denormal_fpenv(positivezero) {
   %result = fadd double 0x8000000000000, 0.0
   ret double %result
 }
 
-define double @tgt() "denormal-fp-math"="positive-zero" {
+define double @tgt() denormal_fpenv(positivezero) {
   ret double 0.0
 }
diff --git a/tests/alive-tv/fp/fdiv-denormal-f32-fold.srctgt.ll b/tests/alive-tv/fp/fdiv-denormal-f32-fold.srctgt.ll
new file mode 100644
index 000000000..b9fb32ec0
--- /dev/null
+++ b/tests/alive-tv/fp/fdiv-denormal-f32-fold.srctgt.ll
@@ -0,0 +1,8 @@
+define float @src() denormal_fpenv(float: positivezero) {
+  %result = fdiv float 0x3810000000000000, 2.000000e+00
+  ret float %result
+}
+
+define float @tgt() denormal_fpenv(float: positivezero) {
+  ret float 0.0
+}
diff --git a/tests/alive-tv/fp/fdiv-denormal-f32-no-fold-1.srctgt.ll b/tests/alive-tv/fp/fdiv-denormal-f32-no-fold-1.srctgt.ll
new file mode 100644
index 000000000..f96e736bc
--- /dev/null
+++ b/tests/alive-tv/fp/fdiv-denormal-f32-no-fold-1.srctgt.ll
@@ -0,0 +1,12 @@
+; ERROR: Value mismatch
+
+; the "float: ieee" here overrides the positivezero for the float type
+
+define float @src() denormal_fpenv(positivezero, float: ieee) {
+  %result = fdiv float 0x3810000000000000, 2.000000e+00
+  ret float %result
+}
+
+define float @tgt() denormal_fpenv(positivezero, float: ieee) {
+  ret float 0.0
+}
diff --git a/tests/alive-tv/fp/fdiv-denormal-f32-no-fold-2.srctgt.ll b/tests/alive-tv/fp/fdiv-denormal-f32-no-fold-2.srctgt.ll
new file mode 100644
index 000000000..902ada1db
--- /dev/null
+++ b/tests/alive-tv/fp/fdiv-denormal-f32-no-fold-2.srctgt.ll
@@ -0,0 +1,12 @@
+; ERROR: Value mismatch
+
+; the float attribute should not apply to doubles
+
+define double @src() denormal_fpenv(float: positivezero) {
+  %result = fdiv double 0x3810000000000000, 2.000000e+00
+  ret double %result
+}
+
+define double @tgt() denormal_fpenv(float: positivezero) {
+  ret double 0.0
+}
diff --git a/tests/alive-tv/fp/fdiv-denormal-fpenv.srctgt.ll b/tests/alive-tv/fp/fdiv-denormal-fpenv.srctgt.ll
new file mode 100644
index 000000000..19f5ee663
--- /dev/null
+++ b/tests/alive-tv/fp/fdiv-denormal-fpenv.srctgt.ll
@@ -0,0 +1,8 @@
+define float @src() denormal_fpenv(positivezero|ieee) {
+  %result = fdiv float 0x3810000000000000, -2.000000e+00
+  ret float %result
+}
+
+define float @tgt() denormal_fpenv(positivezero|ieee) {
+  ret float 0.0
+}
diff --git a/tests/alive-tv/fp/fneg-denormal.srctgt.ll b/tests/alive-tv/fp/fneg-denormal.srctgt.ll
index d44f3f332..7584b109f 100644
--- a/tests/alive-tv/fp/fneg-denormal.srctgt.ll
+++ b/tests/alive-tv/fp/fneg-denormal.srctgt.ll
@@ -1,8 +1,8 @@
-define double @src() "denormal-fp-math"="positive-zero" {
+define double @src() denormal_fpenv(positivezero) {
   %result = fneg double 0x8000000000000
   ret double %result
 }
 
-define double @tgt() "denormal-fp-math"="positive-zero" {
+define double @tgt() denormal_fpenv(positivezero) {
   ret double 0x8008000000000000
 }
diff --git a/tests/alive-tv/params/fn-refinement.srctgt.ll b/tests/alive-tv/params/fn-refinement.srctgt.ll
index 64066ab90..fe131ff3c 100644
--- a/tests/alive-tv/params/fn-refinement.srctgt.ll
+++ b/tests/alive-tv/params/fn-refinement.srctgt.ll
@@ -1,10 +1,10 @@
-define double @src() "denormal-fp-math"="positive-zero" {
+; ERROR: Function attributes not refined
+
+define double @src() denormal_fpenv(positivezero) {
   %result = fadd double 0x8000000000000, 0.0
   ret double %result
 }
 
-define double @tgt() "denormal-fp-math"="ieee" {
+define double @tgt() denormal_fpenv(ieee) {
   ret double 0.0
 }
-
-; ERROR: Function attributes not refined